ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (60)
  • 73.20.Dx  (60)
  • Springer  (60)
  • American Geophysical Union (AGU)
  • Annual Reviews
  • Institute of Physics
  • 1995-1999  (60)
  • 1980-1984
  • 1935-1939
  • Physics  (60)
Collection
  • Articles  (60)
Publisher
  • Springer  (60)
  • American Geophysical Union (AGU)
  • Annual Reviews
  • Institute of Physics
Years
Year
  • 1
    ISSN: 1432-0649
    Keywords: 78.47.+p ; 73.20.Dx ; 71.35,+z
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We use femtosecond time-resolved transmission spectroscopy to study the density and time dependence of transient absorption changes of CdSe nanocrystals. Our data show pronounced absorption saturation up to complete bleaching of the lowest optical transition. At high carrier density the nonlinear spectra show several peaks that can be related to the two lowest quantized electron states. Thetime dependence of the carrier-induced absorption changes indicates an ultrafast relaxation process within the strongly broadened absorption lines.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 61 (1995), S. 467-474 
    ISSN: 1432-0630
    Keywords: 73.20.-r ; 73.20.Dx ; 61.16.Ch
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract It is shown how wire structures a few nanometers wide can be fabricated by decorating step edges at vicinal surfaces. Their growth modes and electronic states are studied using Scanning Tunneling Microscopy (STM) and inverse photoemission. The observed growth modes are two-dimensional analogs of Stranski-Krastanov growth and layer-by-layer growth in three dimensions, e.g., for Cu on stepped Mo(1 1 0) and W(1 1 0), respectively. Contrast between different metals is achieved in STM pictures by resonant tunneling via surface states and image states, with the latter providing a map of the work function. The limit of single atomic rows decorating step edges is studied by inverse photoemission, and an energy shift of 0.4 eV is found for electronic states of step atoms. We expect stripe structures to become useful for the study of two- vs one-dimensional magnetism, for magnetoresistive films, and in the design of anisotropic materials.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-0630
    Keywords: 73.20.Dx ; 13.40. DK
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Analytical expressions for the transmission coefficient and the resonance condition in unsymmetrical rectangular double-barrier structures are derived theoretically by taking into account the mass difference between well and barrier layers. It is found that resonant tunneling with a transmission peak equal to 1 (unity resonance) and resonant tunneling with a transmission peak less than 1 (below unity resonance) may occur in the unsymmetrical double-barrier structures. Two independent conditions are required for unity-resonant transmission: One is the Phase-Difference Condition for Resonance (PDCR) and the other is the Maximum Condition for the Peak Value (MCPV). The below-unity resonant transmission occurs when only condition PDCR holds. It is believed that the two conditions are useful for calculating values of the transmission coefficient and the resonance energy for the unsymmetrical double-barrier structures. They may be useful for resonant tunneling-device fabrication. Furthermore, wave functions of an electron at resonance level are calculated and the confining phenomenon is confirmed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 65 (1997), S. 484-490 
    ISSN: 1090-6487
    Keywords: 73.40.Gk ; 73.20.Dx ; 72.15.Eb ; 71.20.Be
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A new mechanism is proposed for the anomalous tunneling transmittance of a double-barrier quantum-well structure doped with a transition-metal impurity and possessing an intrinsic two-dimensional continuum. The new tunneling channels are due to exponentially-narrow single-particle resonances arising near the edge of a 2D band during tunneling. They are temperature-independent and their contribution to the transmittance can exceed the contribution of the Kondo resonance even at temperatures T〈T K .
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1090-6487
    Keywords: 73.40.Kp ; 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Electron transport through an asymmetric heterostructure with a two-step barrier N+GaAs/N−GaAs/Al0.4Ga0.6As/Al0.03Ga0.97As/N−GaAs/N+GaAs was investigated. Features due to resonance tunneling both through a size-quantization level in a triangular quantum well, induced by an external electric field in the region of the bottom step of the barrier (Al0.03Ga0.97As layer), and through virtual levels in two quantum pseudowells of different width are observed in the tunneling current. The virtual levels form above the bottom step or above one of the spacers (N−GaAs layer) as a result of interference of electrons, in the first case on account of reflection from the Al0.4Ga0.6As barrier and a potential jump at the Al0.03Ga0.97As/N−GaAs interface and in the second case — from the Al0.4Ga0.6As barrier and the potential gradient at the N−GaAs/N+GaAs junction, reflection from which is likewise coherent.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 67 (1998), S. 196-202 
    ISSN: 1090-6487
    Keywords: 73.20.Dx ; 73.23.Hk
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A model is found whereby the Coulomb interaction during electron transport in quantum wires of finite length with current-lead contacts can be taken into account exactly (within the framework of the bosonization method). It is established that the charge density distribution along a wire in the case of the real Coulomb interaction is strongly different from the Luttinger liquid model, where the interaction is assumed to be short-ranged. The charge density near the contacts is found to be much higher than in the model with a short-range interaction, but away from the contacts the two densities are closer to each other.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1090-6487
    Keywords: 42.55.Px ; 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A solution of the nonstationary Schrödinger equation describing the resonance interaction of electrons with a weak rf field is found for asymmetric triple-barrier resonance-tunneling structures with thin, high barriers, and an expression is obtained for the active weak-signal conductivity of such structures. It is found that in a number of cases the probability of quantum resonance transitions from an upper to a lower level can increase sharply when the lower levels are shifted relative to one another.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 68 (1998), S. 915-921 
    ISSN: 1090-6487
    Keywords: 73.20.Dx ; 73.61.−r
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract It is found that various kinds of shell structure which occur at specific values of the magnetic field lead to the disappearance of the orbital magnetization for particular magic numbers in small quantum dots with electron number A〈30.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1090-6487
    Keywords: 81.15.Hi ; 73.20.Dx ; 68.65.+g
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The characteristic features of electronic spectra in Ge/Si (100) heterostructures obtained by molecular-beam epitaxy are investigated by capacitance spectroscopy. It is observed that the self-organization of a Ge film into an island film when the effective germanium thickness exceeds six monolayers is accompanied by the appearance of hole bound states, which can be attributed to size quantization and the Coulomb interaction of carriers in the array of Ge quantum dots.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 68 (1998), S. 673-678 
    ISSN: 1090-6487
    Keywords: 74.20.−z ; 73.20.Dx ; 74.25.Ha ; 11.30.Pb
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract In the theory of mesoscopic superconductivity it is necessary to supplement the coordinates x, y, z with some additional physical characteristics (coordinates) of free space. An adequate description of mesoscopic superconductivity is obtained by introducing a nonrelativistic version of Grassmann spinor coordinates, which are studied in supersymmetric field theories and convert ordinary space into superspace. An experimental check of the proposed description of the superconducting and magnetic properties of metallic nanoparticles would provide a direct confirmation of the concept of superspace.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    ISSN: 1090-6487
    Keywords: 73.20.Dx ; 73.40.Hm ; 84.37.+q
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract It is shown that capacitance spectroscopy can be used to investigate the spin polarization of two-dimensional electronic systems (2DESs). We employed this method to investigate the spin polarization of 2DESs in a GaAs/AlGaAs heterojunction for filling factors of the magneticquantization levels 0.28〈ν〈0.9. It is proved that in the presence of states of the fractional quantum Hall effect with ν f =1/3 and 2/3 the ground state of a 2DES with ν〉2/3 is incompletely spin-polarized.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    ISSN: 1090-6487
    Keywords: 73.20.Dx ; 71.35.−y ; 33.15.Pw
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The experimental results of a study of the fine structure of the levels of excitons localized in InAlAs quantum dots in an AlGaAs matrix are reported. Transformations from optical orientation to alignment and from alignment to orientation, which occur due to the exchange splitting of a dipole-active excitonic doublet and are allowed by the low symmetry of a quantum dot, are observed in a longitudinal magnetic field (Faraday geometry). A comparison of theory with experiment for a self-organized ensemble of quantum dots enables a determination of the character of the distribution over the dipole orientations for resonance optical transitions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 65 (1997), S. 253-258 
    ISSN: 1090-6487
    Keywords: 71.45.Gm ; 73.20.Dx ; 73.40.Lq
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract It is shown that the phase transition of density-wave origin in homogeneous liquids is preceded by fermion condensation. Thus fermion condensation may be observed in low-density electron liquids, neutron stars, and liquid He3. Three-dimensional (3D) and two-dimensional (2D) liquids are considered.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 68 (1998), S. 669-672 
    ISSN: 1090-6487
    Keywords: 71.35.Ji ; 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The ground state of a spatially indirect exciton in type-II quantum dots with a short-range potential acquires nonzero angular momentum in the presence of a magnetic field oriented perpendicular to the plane of the system. The critical magnetic field of the transition to a ground state with nonzero angular momentum depends on the radius of the quantum dot. Such a transition can be observed as quenching of luminescence by a magnetic field in quantum dots of the GaSb/GaAs system, for example.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 66 (1997), S. 431-436 
    ISSN: 1090-6487
    Keywords: 72.20.My ; 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A study is made of the four-terminal Hall junction under the influence of a radiation field. The frequency of the radiation field is tuned to a transition between the energy of a bound state below a conduction subband and the Fermi energy of the incident electrons. Radiation-field-induced resonant dips of the Hall resistance are exhibited at low magnetic fields.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    ISSN: 1090-6487
    Keywords: 85.30.Vw ; 73.20.Dx ; 78.30.Fs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The spontaneous emission of far-infrared radiation (λ≅10–20 μm) from diode structures with vertically coupled InGaAs/AlGaAs quantum dots is observed. This emission is due both to transitions of holes and electrons between size-quantization levels in quantum dots and to transitions from the continuum to a level in a quantum dot. It is observed only when accompanied by lasing at short wavelengths (λ≅0.94 μm) and, like the short-wavelength emission, it exhibits a current threshold. The spontaneous emission of long-wavelength radiation is also observed in InGaAs/GaAs quantum-well laser structures. This radiation is approximately an order of magnitude weaker than that from quantum-dot structures, and it has no current threshold.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 67 (1998), S. 1069-1075 
    ISSN: 1090-6487
    Keywords: 71.10.Hf ; 71.27.+a ; 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract It is shown that additional scattering due to tunneling induces a transition of the system from a non-Fermi-liquid into a Fermi-liquid state as the distance between the Fermi level in the walls and the 2D-band edge is varied in a double-barrier quantum well, doped with transition-metal impurities and having an intrinsic two-dimensional continuum.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    ISSN: 1090-6487
    Keywords: 75.60.Nt ; 75.60.Ch ; 75.70.Cn ; 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract It is shown that under resonance tunneling conditions the energy structure of electric-field domains in doped superlattices is substantially different from a resonance structure. As the impurity concentration decreases, the domain walls become wider and the current hysteresis becomes narrower (collapses) as a result of the mismatch of the resonance levels in the region of a domain wall. A physical interpretation of the criterion for the existence of electric-field domains is given.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    ISSN: 1090-6487
    Keywords: 73.40.Hm ; 72.15.−v ; 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The effect of the nuclear hyperfine interaction on the dc conductivity of 2D electrons under quantum Hall effect conditions at filling factor ν=1 is observed for the first time. The local hyperfine field enhanced by dynamic nuclear polarization is monitored via the Overhauser shift of the 2D conduction electron spin resonance in AlGaAs/GaAs multiquantum-well samples. The experimentally observed change in the dc conductivity resulting from dynamic nuclear polarization is in agreement with a thermal activation model incorporating the Zeeman energy change due to the hyperfine interaction. The relaxation decay time of the dc conductivity is, within experimental error, the same as the relaxation time of the nuclear spin polarization determined from the Overhauser shift. These findings unequivocally establish the nuclear spin origins of the observed conductivity change.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    ISSN: 1090-6487
    Keywords: 73.20.Dx ; 73.20.Hb
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A radical change in the ionization energy of the donor impurity Si in a GaAs/AlGaAs double-well heterostructure is observed experimentally when the electronic wave function is relocated in an electric field. The ionization energy of the impurity decreases from 15.5 meV to 0 when the voltage across the structure changes by less than 1 V. The Stark effect would give a change in the ionization energy of not more than 3 meV.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 69 (1999), S. 250-254 
    ISSN: 1090-6487
    Keywords: 73.20.Dx ; 61.46.+w
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A study is made of the Förster energy transfer from an excited semiconductor quantum dot to an organic material surrounding the dot. A quantum-mechanical microscopic description of a Wannier-Mott exciton in a quantum dot is employed together with a macroscopic description of the organic medium. The calculations show that for II–VI semiconductors such transfer can occur in a time of the order of tens of picoseconds, which is much shorter than the lifetime of an excitation in a quantum dot in the absence of transfer. Therefore, just as for quantum wells, the energy transfer mechanism considered can be a quite efficient means for pumping organic sources of radiation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 64 (1996), S. 460-466 
    ISSN: 1090-6487
    Keywords: 73.20.Dx ; 76.40.+b
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A number of effects associated with the curvature of the surface on which a two-dimensional (2D) electron gas is placed are studied. The most significant effect in an external magnetic field (which for 2D electrons becomes effectively nonuniform) is the lifting of the degeneracy of the Landau levels. The intensity and shape of the cyclotron resonance line (inhomogeneously broadened) for different polarizations and the corrections to the Hall constant are found for the example of a circular cylinder. A picture of the quantization of the conductance that is qualitatively different from the case of a flat strip is obtained for a quasi-one-dimensional quantum wire in the form of a hollow cylinder. It is shown that in contradistinction to the planar case the spectrum of 2D electrons on the curved surface is sensitive to the sign of the spin-orbit coupling constant (for a fixed sign of the curvature). For hetero-junctions, for example, this opens up new possibilities for extracting information about their “hidden parameters.”
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 64 (1996), S. 592-600 
    ISSN: 1090-6487
    Keywords: 72.90.+y ; 73.20.Dx ; 73.40.−c ; 73.90.−f
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Macroscopic charge quantization is analyzed in the case in which thermal activation across trapping barriers dominates over tunneling and the barrier heights are comparable to the charging and thermal energies. Barrier suppression, the image force due to the finite electron charge, and the contribution of unstable charge states are considered. The effects considered may partly account for recent experimental data on high-temperature single-electronics in semiconductor and granulated systems.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    ISSN: 1090-6487
    Keywords: 73.61.Ey ; 73.40.Kp ; 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The transformation of quantum size levels into virtual levels upon a change in the electric field in an AlAs/GaAs superlattice located in the i region of a p-i-n structure is studied experimentally and theoretically. It is shown that an interfacial state at the boundary between the superlattice and the p-GaAs contact layer results in a resonant increase in the probability of photoelectron tunneling from the contact into the superlattice via Wannier-Stark levels.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 70 (1999), S. 390-395 
    ISSN: 1090-6487
    Keywords: 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract It is shown that when a strong ac electric field acts on an electron in a double quantum well, the dipole moment is an almost periodic function of the dc voltage applied to the structure. An antipolarization effect — the structure is polarized in a direction opposite to the external field — appears during one half of the period.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 70 (1999), S. 410-414 
    ISSN: 1090-6487
    Keywords: 73.20.Dx ; 71.10.Ca
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The Landau quantization for the electron gas on the surface of a sphere is considered. It is shown that in the regime of strong fields the lowest energy states are those with magnetic quantum numbers m of order of Φ /Φ0, the number of magnetic flux quanta piercing the sphere. For an electron gas of low density (semiconducting situation) it leads to the formation of an electronic stripe on the equator of the sphere in high fields.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    ISSN: 1090-6487
    Keywords: 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract When a voltage is applied to double quantum wells based on AlGaAs/GaAs heterostructures with contact regions (n-i-n structures), a two-dimensional (2D) electron gas appears in one of the quantum wells. Under illumination which generates electron-hole pairs, the photoexcited holes become localized in a neighboring quantum well and recombine radiatively with the 2D electrons (tunneling recombination through the barrier). The appearance, ground-state energy, and density of the degenerate 2D electron gas are determined from the structure of the Landau levels in the luminescence and luminescence excitation spectra as well as from the oscillations of the radiative recombination intensity in a magnetic field with detection directly at the Fermi level. The electron density is regulated by the voltage between the contact regions and increases with the slope of the bands. For a fixed slope of the bands the 2D-electron density has an upper limit determined by the resonance tunneling of electrons into a neighboring quantum well and subsequent direct recombination with photoexcited holes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 65 (1997), S. 909-914 
    ISSN: 1090-6487
    Keywords: 78.20.Bh ; 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The optical orientation of electron spins in heavily doped semiconductor structures with a valence band that is split as a result of size quantization or uniaxial deformation is investigated theoretically. It is shown that lowering the Fermi level by doping and by lowering the temperature should lead to sharp changes in the photon-energy-dependence of the average spin of the excited electrons in structures excited by circularly polarized light. This effect is due to an interchange of the dominant contribution of transitions from a light-hole subband and transitions from the heavy-hole subband in absorption.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 65 (1997), S. 215-216 
    ISSN: 1090-6487
    Keywords: 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Quantum dots based on materials with long-lived terahertz vibrations are studied. It is shown that squeezed states of such vibrations can result in microwave-frequency modulation of the optical radiation absorbed at electronic transitions in quantum dots.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    ISSN: 1090-6487
    Keywords: 73.61.Ey ; 73.20.Dx ; 07.79.Fc ; 61.16.Ch
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We study InP quantum dots which are prepared by strain induced self-assembly on GaAs substrates with a GaInP buffer layer using a near field scanning optical microscope operating at near liquid He bath temperatures in the collection mode. Single quantum dots are identified spatially and spectrally due to their photoluminescence spectrum. Series of luminescence lines due to single dots of different sizes are discussed in terms of dot height and width fluctuations.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 66 (1997), S. 298-303 
    ISSN: 1090-6487
    Keywords: 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The possibility of performing single-electron computing without dissipation in an array of tunnel-coupled quantum dots is studied theoretically, taking the spin gate NOT (inverter) as an example. It is shown that the logical operation can be implemented at the stage of unitary evolution of the electron subsystem, although complete switching of the inverter cannot be achieved in a reasonable time at realistic values of model parameters. The optimal input magnetic field is found as a function of the interdot tunneling energy and intradot Coulomb repulsion energy.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    ISSN: 1090-6487
    Keywords: 73.20.Dx ; 73.20.Mf ; 78.60.−b ; 78.55.Cr
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The radiative recombination spectra of two-dimensional electrons with free photoexcited holes are investigated for a wide variety of GaAs/ AlGaAs quantum wells, with different thicknesses and electron densities. It is found that for certain, close to integral, filling factors an intense line corresponding to an Auger process — radiative recombination with the emission of an additional magnetoplasmon — appears in the luminescence spectrum. The new line is shifted to lower energies with respect to the zero Landau level, and the magnetic field dependence of the energy splitting between these lines agrees with the theoretical concepts of the dispersion of magnetoplasmon excitations. This makes it possible to estimate the magnetoplasmon energy at the roton minimum.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    ISSN: 1090-6487
    Keywords: 78.66.Fd ; 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Terahertz emission accompanying heating of two-dimensional electrons by a strong electric field applied along size-quantized GaAs/AlGaAs layers is observed and investigated. The emission is due to indirect optical transitions of hot electrons in the bottom size-quantization band. The experimentally obtained emission spectra are compared with the spectra calculated taking into account scattering of electrons by optical phonons, impurities, and interfacial roughness and electron-electron scattering. Satisfactory agreement is obtained. The temperature of the hot electrons is determined from a comparison of the spectra.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    ISSN: 1090-6487
    Keywords: 73.20.Dx ; 42.50.Gy ; 33.80.Be
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A mechanism is proposed for obtaining intraband population inversion of electrons in size-quantization levels through the injection of electron-hole pairs into the i region of a heterostructure with quantum wells or quantum dots. Key elements of the mechanism are the simultaneous generation of interband (hv≈E g ) near-IR radiation and the presence of a “metastable” level. In quantum wells such a level can be produced by making use of the weak overlap of the wave functions of electrons in the levels of a quantum well of complicated configuration and exploiting the characteristic features of the interaction of electrons with optical phonons in polar semiconductors. In quantum dots such a level forms as a result of the phonon bottleneck effect. Estimates are made of the gain for mid-IR radiation in intraband optical transitions of electrons.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    ISSN: 1090-6487
    Keywords: 73.61.Ph ; 73.50.−h ; 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Light-induced conformational transformations of the naphthacenequinone (NQ) molecules are observed by scanning tunneling microscopy (STM). NQ molecules packed in a Langmuir-Blodgett (LB) film are shown to form stable ordered structures on a surface of highly oriented pyrolytic graphite (HOPG). The local density of electronic states is found to exhibit the distinct peak which is characteristic of two-dimensional conductivity. An additional subband of empty electronic states is found for NQ molecules in form A but not in form B. The constant-height STM images of individual molecules in form A demonstrate an additional structure that is indicative of a conformational transition of the NQ molecules. This transition involves the transfer of the phenoxy group from one oxygen to another.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 64 (1996), S. 231-236 
    ISSN: 1090-6487
    Keywords: 73.20.Dx ; 84.30.Bv ; 85.30.Vw
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A new approach to the implementation of certain logical functions in quantum-dot gates for single-electron computing is proposed. It is shown that placing a gate in a uniform external magnetic field allows one to construct gates with 1) symmetric physical truth tables and 2) large (in some cases close to saturated) absolute magnitude of the average spin at the output dots. Thus two serious obstacles are removed which otherwise could present a problem in the fabrication of a set of coupled quantum-dot gates.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 68 (1998), S. 732-737 
    ISSN: 1090-6487
    Keywords: 73.20.Dx ; 73.40.Hm ; 75.70.Cn
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Self-induced filamentation of the current near the edges of a sample in the Hall geometry has been observed in the quantum-Hall-effect regime in a two-dimensional electronic system arising near a GaAs/AlGaAs heterojunction. If in the case of integer values of the filling factor ν averaged over the sample the currents flowing along opposite edges are approximately the same, then away from such a value within the quantum plateau the current is increasingly concentrated near that edge of the sample where the local value of ν is closer to being an integer. When the direction of the magnetic field or of the current changes, the filament switches to the opposite edge of the sample.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    ISSN: 1090-6487
    Keywords: 73.20.Mf ; 73.20.Dx ; 85.30.Mn
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The effect of absorption of nonequilibrium acoustical phonons on the intensity of recombination of a two-dimensional electron gas in a magnetic field is investigated. The nonequilibrium acoustical phonons are emitted in the relaxation of electrons in a tunnel junction deposited on the back side of a sample with a two-dimensional electronic channel. It is demonstrated that the optical signal showing the intensity of the recombination of nonequilibrium electrons from a photoexcited size-quantization subband can serve as a sensitive detector of acoustical phonons. Because the general heating of two-dimensional carriers and the intersubband transitions stimulated by the absorption of nonequilibrium acoustical phonons lead to effects of different sign, the useful signal can be discriminated unambiguously.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    ISSN: 1090-6487
    Keywords: 73.20.Dx ; 68.65.+g ; 71.35.−y
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The change in the properties of excitonic states near anticrossing is investigated experimentally. It is shown that the phase relaxation time of light excitons in a GaAs/AlGaAs symmetric double quantum well increases by a factor of five as a result of mixing of the energy states of light and heavy excitons.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    ISSN: 1090-6487
    Keywords: 73.20.Dx ; 71.20.Gj ; 61.44.Br
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The nature of two-dimensional incommensurate superlattices Ll2 (MM) obtained in the precious-metals alloys Au3 Cu and Cu3 Pd is investigated on the basis of first-principles calculations of the electronic structure. It is shown that their stability can be explained by the opening of energy gaps on coinciding sections of the Fermi surface in two mutually perpendicular directions. It is important that this explanation holds only if the superlattice is treated as a superstructure with respect to ordinary superstructures (Ll2): the electronic spectrum of the superstructure and not the disordered alloy (as in the existing electronic theory of one-dimensional long-period structures) should serve as the starting spectrum. Arguments supporting the fact that in a number of quasicrystal-line substances the Ll2 (MM) phases fall between incommensurate systems and quasicrystals are presented.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 66 (1997), S. 588-593 
    ISSN: 1090-6487
    Keywords: 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract In low-dimensional systems with an asymmetric quantizing potential, an asymmetric electron energy spectrum ε(p)≠ε(−p), where p is the electron momentum, arises in the presence of a magnetic field. A consequence of such an energy spectrum is that momentum transfer to the electron system in mutually opposite directions in the presence of an external perturbation is different. Therefore, in the presence of a standing electromagnetic wave momentum is transferred from the wave to the electrons, which gives rise to a new type of electromotive force.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    ISSN: 1090-6487
    Keywords: 72.15.Gd ; 72.20.My ; 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A new phenomenon is observed experimentally in a heavily doped asymmetric quantum-size structure in a magnetic field parallel to the quantum-well layers — a transverse magnetoresistance which is asymmetric in the field (there can even be a channge in sign) and is observed in the case that the structure has a built-in lateral electric field. A model of the effect is proposed. The observed asymmetry of the magnetoresistance is attributed to an additional current contribution that arises under nonequilibrium conditions and that is linear in the gradient of the electrochemical potential and proportional to the parameter characterizing the asymmetry of the spectrum with respect to the quasimomentum.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    ISSN: 1090-6487
    Keywords: 73.61.Ey ; 73.20.Dx ; 63.22.+m
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The energy splitting of fundamental localized transverse optical (TO1) phonon modes in GaAs/AlAs superlattices and quantum wires grown by molecular-beam epitaxy on a faceted (311)A GaAs surface is observed by Raman spectroscopy. The form of the Raman scattering tensor makes it possible to observe the TOx and TOy modes separately, using different scattering geometries the y and x axes are the directions of displacement of the atoms and are directed parallel and transverse to the facets on the (311)A surface). Enhancement of the splitting of the TO1x and TO1y modes is observed as the average thickness of the GaAs layers is decreased from 21 to 8.5 Å. The splitting is probably due to the effect of the corrugation of the GaAs/AlAs (311)A hetero-interface on the properties of localized phonon modes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    ISSN: 1090-6487
    Keywords: 73.20.Dx ; 73.40.Hm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract It is shown that the characteristic features of the chemical potential for 2D electrons in a magnetic field, which lead to sharp dips in the magnetic field dependence of the capacitance of a 2D system, also affect the electrostatic potential distribution in the direction of the transport current flowing through a 2D Corbino disk under conditions of integral magnetic filling factor. The associated details of the temperature dependence of the electrostatic potential distribution, the distances to the screening electron, and the transport potential difference at the Corbino edges are investigated. The possibilities of experimentally observing these features of the electrostatic potential distribution along a Corbino disk with a transport current under conditions of the quantum Hall effect are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    ISSN: 1090-6487
    Keywords: 73.20.Dx ; 73.40.Hm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We employ a magnetocapacitance technique to study the spectrum of the soft two-subband (or double-layer) electron system in a parabolic quantum well with a narrow tunnel barrier at the center. In this system, when unbalanced by gate depletion, two sets of quantum oscillations are observed at temperatures T≳30 mK: one originates from the upper electron subband in the closer-to-the-gate part of the well, and the other indicates the existence of common gaps in the spectrum at integer fillings. For the lowest filling factors υ=1 and υ=2, both the presence of a common gap down to the point of the one-to two-subband transition and their nontrivial magnetic field dependences point to magnetic-field-induced hybridization of electron subbands.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    ISSN: 1090-6487
    Keywords: 78.66.Fd ; 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The interwell radiative recombination from biased double quantum wells (DQW) in pin GaAs/AlGaAs heterostructures is investigated at different temperatures and external electrical fields. The luminescence line of interwell recombination of spatially separated electron-hole pairs exhibits systematic narrowing with temperature increase from 4.5 to 30 K. A theoretical model is presented which explains the observed narrowing in terms of lateral thermally activated tunneling of spatially separated e-h pairs localized by random potential fluctuations in the quantum wells.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    ISSN: 1090-6487
    Keywords: 73.20.Dx ; 71.35.Cc
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The recombination spectra of excitons and excitonic complexes in un-doped GaAs/AlGaAs single quantum wells are investigated. It is shown on the basis of a study of the magnetic-field dependence of the emission spectra and the degree of optical orientation in zero magnetic field and on the basis of electrooptic measurements that not only the density but also the sign of the charge carriers in a well depend strongly on the photoexcitation energy. It is shown on the basis of a comparative analysis of the spin splitting of the recombination lines of free and bound excitons that the recombination line which was attributed earlier to a positively charged exciton corresponds to the recombination of an exciton bound on a neutral acceptor.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 68 (1998), S. 662-668 
    ISSN: 1090-6487
    Keywords: 85.30.Mn ; 73.20.Dx ; 73.20.Mf
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Resonant tunneling is accompanied by the accumulation of 2D electrons in the quantum well between the barriers of resonant tunneling diodes. In high-quality structures this gives a Z-shaped current-voltage characteristic, and it is shown that self-excitation of 2D plasmons occurs in this quantum well for any external circuit at completely realistic parameters of the structures.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 69 (1999), S. 616-622 
    ISSN: 1090-6487
    Keywords: 71.35.Lk ; 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The effect of a random field due to impurities, boundary irregularities, and so on, on the superfluidity of a three-dimensional system of excitons and a quasi-two-dimensional system of direct or spatially indirect excitons is studied. The influence of a random field on the density of the superfluid component in the indicated excitonic systems at low temperatures T is investigated. The interaction between excitons is taken into account in the ladder approximation. For quasi-two-dimensional excitonic systems in a random field the Kosterlitz-Thouless temperature in the superfluid state is calculated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    Electronic Resource
    Springer
    JETP letters 70 (1999), S. 488-490 
    ISSN: 1090-6487
    Keywords: 73.40.Kp ; 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Nonlinear waves in a two-dimensional electronic plasma with metal screening gates are investigated. It is shown that solitons described by the KdV equation exist in such a system.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    ISSN: 1573-7357
    Keywords: 79.60.Bm ; 73.20.Dx ; 74.70.Ad ; 74.80.Dm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract With high-resolution (≈22 meV) angle-resolved photoemission spectroscopy, the Fermi surface of the first copper free layered-perovskite superconductor, Sr2RuO4, was determined. We observed three bands to cross the Fermi energy in qualitative agreement with LDA band structure calculations; one electron-like surface encircling the $$\overline \Gamma$$ point in the projected Brillouin zone, and two hole-like surfaces around the $$\overline X$$ point. The most striking aspect of the measurements is the observation of an extended van Hove singularity. It is located 17 meV below the Fermi energy and extends around the $$\overline M$$ point for about 0.2 Å−1 along both the $$\overline \Gamma$$ — $$\overline M$$ — $$\overline \Gamma$$ and the $$\overline X$$ — $$\overline M$$ — $$\overline X$$ directions.These observations demonstrate that van Hove singularities near the Fermi surface are a more generic feature of layered oxides, and call for a clarification of their exact role in oxide superconductivity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Electronic Resource
    Electronic Resource
    Springer
    Journal of low temperature physics 99 (1995), S. 337-342 
    ISSN: 1573-7357
    Keywords: 73.20.Dx ; 74.70.Vy ; 75.40.Gb ; 76.60.Cq
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We analyze the spectrum of magnetic excitations as observed by neutron diffraction and NMR experiments in Y Ba2Cu3O6+x, in the frame of the single-band t-t′-J model in which the next-nearest-neighbour hopping term has been introduced in order to fit the shape of the Fermi surface revealed in photoemission. Within the slave-boson approach, we have as well examined the d-wave superconducting state, and the singlet-RVB phase appropriate to describe the normal state of heavily-doped systems. Our calculations show a smooth evolution of the spectrum from one phase to the other, with the existence of a spin-gap in the frequency-dependence of χ″(→Q,w)-The value of the threshold of excitations EG is found to increase with doping, while the characteristic temperature-scale Tm at which the spin-gap opens, exhibits a regular decrease, reaching Tc only in overdoped regime. This very atypical combined variation of EG and Tm with doping results of strong-correlation effects in presence o realistic band structure. We point out the presence of a resonance in the w-dependence of χ″(→Q,w) in good agreement with the neutron diffraction results obtained at x = 0.92 and x = 1.0. This resonance is analyzed as a dynamical Kohn anomaly of the second kind in the Cooper channel. Finally, we examine the →q-dependence of the dynamical susceptibility allowing to study the magnetic correlation length ξ as a function of doping, frequency and temperature.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Springer
    Journal of low temperature physics 99 (1995), S. 583-585 
    ISSN: 1573-7357
    Keywords: 72.10.Bg ; 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The Coulomb 1/r-interaction plays an important role in quantum wires. We study the interplay between this long range interaction and impurity. For a single band quantum wire, we find that the transport properties are strongly modified. The linear conductance G is found to vanish with temperature as G ∼ exp[-ν ln3/2(1/T)]and the current-voltage characteristics acquires a threshold-like behavior.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    Electronic Resource
    Springer
    Journal of low temperature physics 101 (1995), S. 433-438 
    ISSN: 1573-7357
    Keywords: 73.20.Dx ; 67.40.Hf ; 73.50.Fq
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The Wigner solid (WS) on a liquid4He surface is accompanied with the periodic surface deformation, i.e. the ripplons whose wavevectors equal the reciprocal WS lattice vectors. This unique situation plays a crucial role in the dynamics of the WS. We have performed an extensive measurement of the ac Corbino conductivity σxx. The WS conductivity shows extremely nonlinear behavior, and it jumps abruptly at a certain input voltage. The threshold input voltage Vth varies as VthαB−0.8f−1ns 1.5E⊥, where B, f, ns, and E⊥ are magnetic field, frequency, electron density and pressing electric field, respectively. We have interpreted the σxx jump as the collective sliding of the electrons out of the surface deformation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    ISSN: 1573-7357
    Keywords: 79.60.Bm ; 73.20.Dx ; 74.70.Ad ; 74.80.Dm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Substituting Y in orthorhombic (Y,RE)Ba2Cu3O7 by any rare-earth element RE has generally little effect on the superconducting properties. For RE = Pr, however, superconductivity is completely suppressed. To elucidate this effect we have studied the unoccupied electronic structure of PrxY1−xBa2Cu3O7−y (x = 0.0,0.4, 0.8) by polarization-dependent O1s x-ray absorption spectroscopy on detwinned single crystals. Along with the comparison of undoped (y ≈ 0.9) to the doped materials (y ≈ 0.1), this allows a test of the current theoretical explanations for the suppression of superconductivity. While we can rule out models involving hole filling or charge transfer from planes to chains our data is consistent with approaches based on Pr4f−02pπ hybridization.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    Springer
    Journal of low temperature physics 101 (1995), S. 439-444 
    ISSN: 1573-7357
    Keywords: 73.20.Dx ; 67.55.-s
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We have measured the mobility of surface state electrons (SSE) on liquid3He, μ3, aiming to study the elementary surface excitations of the Fermi liquid. A gradual increase of μ3 below 300 mK is attributed to the scattering of electrons by ripplons. Ripplons do exist in3He down to 100 mK. We observe an abrupt decrease of μ3, due to the transition to the Wigner solid (WS). The dependences of the WS conductivity and mobility on temperature and magnetic field differ from the SSE behavior on liquid4He.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 98 (1995), S. 503-507 
    ISSN: 1434-6036
    Keywords: 71.10.+x ; 73.20.Dx ; 03.65.-w
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The dynamic effect of electrons in a double quantum well under the influence of a monochromatic driving laser field is investigated. Closed-form solutions for the quasienergy and Floquet states are obtained with the help ofSU (2) symmetry. For the case of weak interlevel coupling, explicit expressions of the quasienergy are presented by the use of perturbation theory, from which it is found that as long as the photon energy is not close to the tunnel splitting, the electron will be confined in an initially occupied eigenstate of the undriven system during the whole evolution process. Otherwise, it will transit between the lowest two levels in an oscillatory behavior.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 98 (1995), S. 273-277 
    ISSN: 1434-6036
    Keywords: 05.45.b ; 05.40+j ; 71.25.−s ; 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Numerical study of the parametric motion of energy levels in a model system built on Random Matrix Theory is presented. The correlation function of levels' slopes (the so called velocity correlation function) is determined numerically and compared with its limiting analytic form when available. A simple analytic form of the velocity correlation function is proposed which very well reproduces numerical data. The results should be directly applicable in studies of chaotic or mesoscopic systems.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 98 (1995), S. 435-436 
    ISSN: 1434-6036
    Keywords: 73.50.Jt ; 73.20.Dx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We report a new approach to the description of quantum transport phenomena of strongly correlated electrons on the liquid helium surface in a magnetic field. The self-consistent Born approximation (SCBA) theory was re-established for a generalized collision frequency function ν instead of conductivity tensor components, to be valid for any ratio of the cyclotron frequency ωc to ν. It was found that for electron-vapour atom scattering the collision frequency increases faster with the magnetic field than ωc, which explains the discrepancy between experimental data and the previous SCBA theory.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 35 (1995), S. 285-297 
    ISSN: 1434-6079
    Keywords: 36.40. +d ; 73.20.Mf ; 73.20.Dx ; 21.60.Cs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The local spin-density approximation is used to calculate ground- and isomeric-state geometries of jellium clusters with 2 to 22 electrons. The positive background charge of the model is completely deformable, both in shape and in density. The model has no input parameters. The resulting shapes of the clusters exhibit breaking of axial and inversion symmetries; in general the shapes are far from ellipsoidal. Those clusters which lack inversion symmetry are extremely soft against odd-multipole deformations. Some clusters can be interpreted as molecules built from magic clusters. The deformation produces a gap at the Fermi level. This results in a regular odd-even staggering of the total energy per electron and of the HOMO level. The strongly deformed 14-electron cluster is semimagic. Stable isomers are predicted. The splitting of the plasmon resonance due to deformation is estimated on a classical argument.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...