ALBERT

Beschreibung: Formation of turions, the vegetative perennation organs, plays an important role in the survival strategy of Spirodela polyrhiza (L.) Schleiden. Turion formation [quantified as number of turions formed per frond; specific turion yield (SY)] was investigated in 27 clones collected from a wide geographical range. The Pearson correlation was tested with (1) duration of growing season (monthly average temperature of ≥10°C), (2) relative growth rate of the fronds, (3) longitude and latitude, and (4) several climatic parameters, in all possible single and multiple regressions. All single coefficients of determination were below 0.10. The highest correlation (R2 = 0.61; adjusted for the number of explaining variables 0.54) was found in a multiple linear regression with the following five parameters: average temperatures over the year and during the growing season, duration of the growing season and precipitation over the year and during the growth period. All these parameters were shown to have significant contributions. This equation was used successfully to predict the SY of five newly isolated clones. Finally, on the basis of all 32 clones the following conclusions were drawn: The mean annual temperature has the highest impact. It is suggested that lower temperatures decrease the survival rate of turions and that adaptation refers to increasing SY. The different levels of SY in the clones (ranging from SY = 0.22 to 5.9) were detected even after several years of in vitro cultivation. It is therefore assumed that these adaptations to the climatic conditions are genetically determined.

Beschreibung: The GPS orbit precision of the IGS ultra-rapid predicted (IGU-P) products has been remarkably improved since 2007. However, the satellite clock offsets of the IGU-P products have not shown sufficient high-quality prediction to achieve sub-decimeter precision in real-time precise point positioning (RTPPP), being at the level of 1–3 ns (30–90 cm) RMS in recent years. An improved prediction model for satellite clocks is proposed in order to enhance the precision of predicted clock offsets. First, the proposed prediction model adds a few cyclic terms to absorb the periodic effects, and a time adaptive function is used to adjust the weight of the observation in the prediction model. Second, initial deviations of the predictions are reduced by using a recomputed constant term. The simulation results have shown that the proposed prediction model can give a better performance than the IGU-P clock products and can achieve precision better than 0.55 ns (16.5 cm) in real-time predictions. In addition, the RTPPP method was chosen to test the efficiency of the new model for real-time static and kinematic positioning. The numerical examples using the data set of 140 IGS stations show that the static RTPPP precision based on the proposed clock model has been improved about 22.8 and 41.5 % in the east and height components compared to the IGU-P clock products, while the precisions in the north components are the equal. The kinematic example using three IGS stations shows that the kinematic RTPPP precision based on the proposed clock model has improved about 30, 72 and 44 % in the east, north and height components.

Beschreibung: The influence of plant and canopy architecture on canopy bidirectional reflectance and the bidirectional reflectance distribution function (BRDF) is the subject of this paper. To understand BRDF-influenced reflectance signals, this influence must be identified and quantified, which requires detailed knowledge concerning the structure and BRDF of the observed canopies. In situ BRDF measurements of canopies are time consuming and depend on the availability of a field goniometer. In contrast to field measurements, computer-based simulations of the canopy BRDF offer an alternative approach that considers parameter-driven setups of virtual canopies under constant illumination conditions. This paper presents the hyperspectral simulation of canopy reflectance (HySimCaR) system, which has been developed in the context of the EnMAP mission. This spectral, spatial, and temporal simulation system consists of detailed virtual 3-D cereal canopies of different phenological stages, whose geometries are linked to the corresponding spectral information. The system enables the simulation of realistic bidirectional reflectance spectra on the basis of virtual 3-D scenarios by incorporating any possible viewing position with ray- tracing techniques. The parameterization of a number of canopy structure parameters, such as phe nological stage, row distance, and row orientation, enables the modeling of the bidirectional reflectance and, based on them, the approximation of the BRDF for many structurally different cereal canopies. HySimCaR has been validated with respect to structural and spectral accuracy using three cereal types, namely, wheat, rye, and barley, at 13 different phenological stages. The results show that the virtual cereal canopies are re-created in a realistic way, and it is possible to model their detailed canopy bidirectional reflectance and their BRDF using HySimCaR.

Beschreibung: It is disputed whether Terrae Rossae form mainly out of the bedrock residue, from allochthonous material like aerosols, or by isovolumetric replacement. Furthermore, whether they are mainly relic soils or are still forming is subject to debate. These questions were addressed by comparing the geochemistry of several limestone and basalt based Red Mediterranean Soils with Lithosols on sandstone and limestone in Jordan. The bedrock residue was included at all test sites. Paleosols and initial soils on the limestone Regolith of historic ruins delivered insights into the possible time frame of soil development. A major reduction of elements in the soils compared to bedrock could be observed for CaO in carbonaceous, SiO2 in arenaceous, and Fe2O3 and MgO in basaltic rocks. All Terrae Rossae, however, are characterised by a significant increase of SiO2, Al2O3, TiO2, Fe2O3, K2O, and a range of mainly metallic minor elements that cannot be derived from the bedrock. A reasonable explanation could be input via aeolian transfer of minerals, with clay minerals as the major carrier plus quartz. This input probably originates in Egypt and Sudan and has remained largely unchanged over long periods. Growing aridity during the Holocene has apparently increased the share of silt while clay deposition and soil development has been reduced. At some sites, metasomatic processes have contributed to soil development and might help to explain the depth of some profiles. However, formation of red soils during the Holocene seems very limited, and the Red Mediterranean Soils may represent remains of a paleolandscape.

Beschreibung: Based on cosmogenic 10Be and 26Al analyses in 15 individual detrital quartz pebbles (16e21 mm) and cosmogenic 10Be in amalgamated medium sand (0.25e0.50 mm), all collected from the outlet of the upper Gaub River catchment in Namibia, quartz pebbles yield a substantially lower average denudation rate than those yielded by the amalgamated sand sample. 10Be and 26Al concentrations in the 15 indi- Accepted 9 April 2012 Available online xxx vidual pebbles span nearly two orders of magnitude (0.22 ± 0.01 to 20.74 ± 0.52 x 10 6 10 Be atoms g-1 and 1.35 ± 0.09 to 72.76 ± 2.04 x 106 26Al atoms g-1, respectively) and yield average denudation rates of w0.7 m Myr-1 (10Be) and w0.9 m Myr-1 (26Al). In contrast, the amalgamated sand yields an average Keywords: Beryllium-10 10Be concentration of 0.77 ± 0.03 x 106 atoms g-1, and an associated mean denudation rate of Aluminium-26 Neon-21 Cosmogenic nuclide Grain size bias Namibia 9.6 ± 1.1 m Myr-1, an order of magnitude greater than the rates obtained for the amalgamated pebbles. The inconsistency between the 10Be and 26Al in the pebbles and the 10Be in the amalgamated sand is likely due to the combined effect of differential sediment sourcing and longer sediment transport times for the pebbles compared to the sand-sized grains. The amalgamated sands leaving the catchment are an aggregate of grains originating from all quartz-bearing rocks in all parts of the catchment. Thus, the cosmogenic nuclide inventories of these sands record the overall average lowering rate of the landscape. The pebbles originate from quartz vein outcrops throughout the catchment, and the episodic erosion of the latter means that the pebbles will have higher nuclide inventories than the surrounding bedrock and soil, and therefore also higher than the amalgamated sand grains. The order-of-magnitude grain size bias observed in the Gaub has important implications for using cosmogenic nuclide abundances in deposi- tional surfaces because in arid environments, akin to our study catchment, pebble-sized clasts yield substantially underestimated palaeo-denudation rates. Our results highlight the importance of carefully considering geomorphology and grain size when interpreting cosmogenic nuclide data in depositional surfaces.

Beschreibung: Author(s): Y. Lutsyshyn, G. E. Astrakharchik, C. Cazorla, and J. Boronat We study the zero-temperature quantum phase transition between liquid and hcp solid 4 He. We use the variational method with a simple yet exchange-symmetric and fully explicit wave function. It is found that the optimized wave function undergoes spontaneous symmetry breaking and describes the quantum... [Phys. Rev. B 90, 214512] Published Thu Dec 11, 2014

Beschreibung: Author(s): L. Z. Deng, B. Lv, Z. Wu, Y. Y. Xue, W. H. Zhang, F. S. Li, L. L. Wang, X. C. Ma, Q. K. Xue, and C. W. Chu We report a detailed investigation on the superconductivity in eight 1–4 unit-cell (UC) FeSe films on SrTiO 3 substrates by measuring their magnetization and sheet resistance in a field between 5×10 −2 and 7×10 4  Oe over the last one and a half years as a function of temperature and frequency, from 2 t... [Phys. Rev. B 90, 214513] Published Thu Dec 11, 2014

Beschreibung: Author(s): Yachin Ivry, Chung-Soo Kim, Andrew E. Dane, Domenico De Fazio, Adam N. McCaughan, Kristen A. Sunter, Qingyuan Zhao, and Karl K. Berggren Thin superconducting films form a unique platform for geometrically confined, strongly interacting electrons. They allow an inherent competition between disorder and superconductivity, which in turn enables the intriguing superconducting-to-insulating transition and is believed to facilitate the com... [Phys. Rev. B 90, 214515] Published Mon Dec 15, 2014

Beschreibung: Author(s): Andreas Moor, Anatoly F. Volkov, and Konstantin B. Efetov On the basis of coupled Ginzburg-Landau equations we study nonhomogeneous states in systems with two order parameters (OPs). Superconductors with a superconducting OP Δ and a charge- or spin-density wave with amplitude W are examples of such systems. When one OP, say Δ, has a form of a topological d... [Phys. Rev. B 90, 224512] Published Tue Dec 16, 2014

Beschreibung: Author(s): Dale R. Harshman and Anthony T. Fiory In their article, Zhang et al. [Phys. Rev. B 86 , 024516 (2012)PRBMDO10.1103/PhysRevB.86.024516] present a remarkable result for Ax(S)yTiNCl compounds (α-phase TiNCl partially intercalated with alkali A and optionally co-intercalated molecular species S), finding the superconducting transition temper... [Phys. Rev. B 90, 186501] Published Thu Nov 06, 2014

Beschreibung: Author(s): S. Zhang, Masashi Tanaka, and Shoji Yamanaka We have studied the electron-doped α-form TiNCl (FeOCl orthorhombic type) in detail and have found the transition temperature Tc of 18.0 K decreases monotonically with increasing the interlayer spacing d upon co-intercalation of various kinds of organic solvent molecules with alkali atoms. We conclu... [Phys. Rev. B 90, 186502] Published Thu Nov 06, 2014

Beschreibung: Author(s): Po-Yao Chang, Shunji Matsuura, Andreas P. Schnyder, and Shinsei Ryu Noncentrosymmetric superconductors (NCSs), characterized by antisymmetric spin-orbit coupling and a mixture of spin-singlet and spin-triplet pairing components, are promising candidate materials for topological superconductivity. An important hallmark of topological superconductors is the existence ... [Phys. Rev. B 90, 174504] Published Fri Nov 07, 2014

Beschreibung: Author(s): Kangjun Seo and Sumanta Tewari The recent discovery of an incipient charge-density wave (CDW) instability competing with superconductivity in a class of high-temperature cuprate superconductors has brought the role of charge order in the phase diagram of the cuprates under renewed focus. Here, we take a mean field Q1=(2π/3,0) and... [Phys. Rev. B 90, 174503] Published Fri Nov 07, 2014

Beschreibung: Author(s): Kung-Hsuan Lin (林宮玄), Kuan-Jen Wang (王冠仁), Chung-Chieh Chang (張忠傑), Yu-Chieh Wen (溫昱傑), Dzung-Han Tsai (蔡宗翰), Yu-Ruei Wu (吳育叡), Yao-Tsung Hsieh (謝曜聰), Ming-Jye Wang (王明杰), Bing Lv (吕兵), Paul Ching-Wu Chu (朱經武), and Maw-Kuen Wu (吳茂昆) We utilize ultrafast optical spectroscopy to study the quasiparticle relaxation in stoichiometric LiFeAs crystals. According to our temperature-dependent studies, we have observed three electronic phases in LiFeAs. Below the superconducting (SC) temperature Tc (=15 K), the relaxation time of quasipa... [Phys. Rev. B 90, 174502] Published Fri Nov 07, 2014

Beschreibung: Author(s): A. Lipman, R. G. Mints, R. Kleiner, D. Koelle, and E. Goldobin We consider 0-π Josephson junctions consisting of 0 and π regions of lengths L0 and Lπ with critical current densities jc0 and jcπ, respectively. The dependence of the Josephson current on the phase-shift averaged along the junction is derived. We show that these systems exhibit the main features of... [Phys. Rev. B 90, 184502] Published Fri Nov 07, 2014

Beschreibung: Author(s): Jeongseop A. Lee, A. M. Mounce, Sangwon Oh, A. M. Zimmerman, and W. P. Halperin Nuclear magnetic resonance techniques are used to study anomalously high diffusion of methanol in porous silica aerogel. [Phys. Rev. B 90, 174501] Published Mon Nov 03, 2014

Beschreibung: Author(s): Yongkang Luo, Hui-Fei Zhai, Pan Zhang, Zhu-An Xu, Guang-Han Cao, and J. D. Thompson The pressure effect on the newly discovered charge-transferred BiS 2 -based superconductor, Eu 3 Bi 2 S 4 F 4 , with a T c of 1.5 K at ambient pressure, is investigated by transport and magnetic measurements. Accompanied with the enhancement of metallicity under pressures, the onset superconducting transition ... [Phys. Rev. B 90, 220510] Published Wed Dec 17, 2014

Beschreibung: Author(s): Guoqing Wu, F. Zamborszky, A. P. Reyes, P. L. Kuhns, R. L. Greene, and W. G. Clark We report 63,65 Cu-NMR spectroscopy and Knight shift measurements on a single crystal of the electron-doped high-T c superconductor Pr 1.85 Ce 0.15 CuO 4−y with an applied magnetic field (H) up to 26.42 T. A very small NQR frequency is obtained with the observation of the spectrum, which shows an extremely... [Phys. Rev. B 90, 214506] Published Thu Dec 04, 2014

Beschreibung: Author(s): M. P. M. Dean, A. J. A. James, A. C. Walters, V. Bisogni, I. Jarrige, M. Hücker, E. Giannini, M. Fujita, J. Pelliciari, Y. B. Huang, R. M. Konik, T. Schmitt, and J. P. Hill The cuprate high temperature superconductors exhibit a pronounced trend in which the superconducting transition temperature T c increases with the number of CuO 2 planes n in the crystal structure. We compare the magnetic excitation spectrum of Bi 2+x Sr 2−x CuO 6+δ (Bi-2201) and Bi 2 Sr 2 Ca 2 Cu 3 O 10+δ (Bi-2223... [Phys. Rev. B 90, 220506] Published Thu Dec 04, 2014

Beschreibung: Author(s): Alaska Subedi I present the results of first principles calculations of the electronic structure and magnetic interactions for the recently discovered superconductor YFe2Ge2 and use them to identify the possible nature of superconductivity and quantum criticality in this compound. I find that the Fe 3d derived st... [Phys. Rev. B 89, 024504] Published Tue Jan 14, 2014

Beschreibung: Author(s): Huiqian Luo and Hai-Hu Wen We report the transport results of underdoped Bi2+xSr2−xCuO6+δ (0.05≤x≤0.40) single crystals. A close relationship between the upturn of in-plane resistivity [ρab(T)] and the sign of magnetoresistance in the normal state upon Bi substitutions is found. Combining the results of the field and angular ... [Phys. Rev. B 89, 024506] Published Tue Jan 14, 2014

Beschreibung: Author(s): Toshihiro Taen, Hidenori Yagyuda, Yasuyuki Nakajima, Tsuyoshi Tamegai, Oscar Ayala-Valenzuela, Leonardo Civale, Boris Maiorov, Tadashi Kambara, and Yasuyuki Kanai The angular dependence of magnetization was measured in an optimally Co-doped BaFe2As2 single crystal, which is irradiated by 2.6 GeV uranium to introduce columnar defects (CDs). At low fields (H), we observe the irreversible magnetization Mirr insensitive to the angle θ around H∥CDs. The field depe... [Phys. Rev. B 89, 024508] Published Wed Jan 22, 2014

Beschreibung: Author(s): Aurelio Romero-Bermúdez and Antonio M. García-García We study analytically the evolution of superconductivity in clean quasi-two-dimensional multiband superconductors as the film thickness enters the nanoscale region by mean-field and semiclassical techniques. Tunneling into the substrate and finite lateral size effects, which are important in experim... [Phys. Rev. B 89, 024510] Published Wed Jan 22, 2014

Beschreibung: Author(s): X. F. Lu, N. Z. Wang, G. H. Zhang, X. G. Luo, Z. M. Ma, B. Lei, F. Q. Huang, and X. H. Chen We report on a superconductor LiFeO2Fe2Se2 with Tc∼43 K, synthesized via the hydrothermal method. The anti-PbO-type spacer layer of LiFeO2 has been successfully intercalated between the anti-PbO-type FeSe layer, which results in a high-Tc superconductivity in this iron selenide material. In this mat... [Phys. Rev. B 89, 020507] Published Wed Jan 22, 2014

Beschreibung: Author(s): Rong Yu, Jian-Xin Zhu, and Qimiao Si We study the orbital-selective superconducting pairing in a five-orbital t-J1-J2 model for iron pnictides. Depending on the orbital selectivity of electron correlations and the orbital characters along the Fermi surface, the superconducting gap in an A1g pairing state may exhibit anisotropy. This an... [Phys. Rev. B 89, 024509] Published Wed Jan 22, 2014

Beschreibung: Author(s): Ashot Melikyan and M. R. Norman We derive and analyze an effective Ginzburg-Landau (GL) functional for a charge density wave for a model of electrons on a tight-binding square lattice with density-density interactions. We show, using realistic electronic dispersions for the cuprates, that for the simplest GL theory, the preferred ... [Phys. Rev. B 89, 024507] Published Thu Jan 16, 2014

Beschreibung: Author(s): S. R. Park, T. Fukuda, A. Hamann, D. Lamago, L. Pintschovius, M. Fujita, K. Yamada, and D. Reznik In superconducting copper oxides, some Cu-O bond-stretching phonons around 70 meV show anomalous giant softening and broadening of electronic origin, and electronic dispersions have large renormalization kinks near the same energy. These observations suggest that phonon broadening originates from qu... [Phys. Rev. B 89, 020506] Published Tue Jan 21, 2014

Beschreibung: Author(s): Huazhou Wei, Sung-Po Chao, and Vivek Aji Unconventional superconducting states of matter are realized in the presence of strong spin-orbit coupling. In particular, nondegenerate bands can support odd-parity superconductivity with rich topological content. Here we study whether this is the case for Weyl semimetals. These are systems whose l... [Phys. Rev. B 89, 014506] Published Fri Jan 10, 2014

Beschreibung: Author(s): Jacob Linder and Takehito Yokoyama We theoretically study the superconducting proximity effect in silicene, which features massive Dirac fermions with a tunable mass (band gap), and compute the conductance across a normal-superconductor (N-S) silicene junction, the nonlocal conductance of an N-S-N junction, and the supercurrent flowi... [Phys. Rev. B 89, 020504] Published Fri Jan 10, 2014

Beschreibung: Author(s): Sergey L. Bud'ko, Duck Young Chung, Daniel Bugaris, Helmut Claus, Mercouri G. Kanatzidis, and Paul C. Canfield We present the evolution of the initial (up to ∼10 kbar) hydrostatic pressure dependencies of Tc and of the ambient pressure, and the jump in the heat capacity associated with the superconducting transition as a function of Na doping in the Ba1−xNaxFe2As2 family of iron-based superconductors. For Na... [Phys. Rev. B 89, 014510] Published Thu Jan 16, 2014

Beschreibung: Author(s): P. Schlottmann The nesting of the Fermi surfaces of an electron and a hole pocket separated by a nesting vector Q and the interaction between electrons give rise to itinerant antiferromagnetism. The order can gradually be suppressed by mismatching the nesting and a quantum critical point is obtained as the Néel te... [Phys. Rev. B 89, 014511] Published Fri Jan 17, 2014

Beschreibung: Author(s): Wei Chen and Manfred Sigrist Multiferroics with coplanar magnetic order are discussed in terms of a superfluid condensate, with special emphasis on spin supercurrents created by phase gradients of the condensate and the effect of external electric fields. By drawing the analogy to a superconducting condensate, phenomena such as... [Phys. Rev. B 89, 024511] Published Thu Jan 23, 2014

Beschreibung: Author(s): Alex Hayat, Hae-Young Kee, Kenneth S. Burch, and Aephraim M. Steinberg We show that the recombination of Cooper pairs in semiconductors can be used as a natural source of polarization-entangled photons, making use of the inherent angular momentum entanglement in the superconducting state. Our proposal is not based on opposite spin population of discrete energy levels a... [Phys. Rev. B 89, 094508] Published Mon Mar 10, 2014

Beschreibung: Author(s): V. Kozhevnikov, R. J. Wijngaarden, J. de Wit, and C. Van Haesendonck To address unsolved fundamental problems of the intermediate state (IS), the equilibrium magnetic flux structure and the critical field in a high-purity type-I superconductor (indium film) are investigated using magneto-optical imaging with a three-dimensional vector magnet and electrical transport ... [Phys. Rev. B 89, 100503] Published Mon Mar 10, 2014

Beschreibung: Author(s): Miroslav Hopjan and Pavel Lipavský Energy spectra of superconducting nanospheres observed via tunneling spectroscopy are theoretically discussed. In the energy gap we find small peaks which correspond to the two-particle dynamics beyond the mean-field BCS approximation. These peaks promise to be a sensitive test of theories of superc... [Phys. Rev. B 89, 094507] Published Mon Mar 10, 2014

Beschreibung: Author(s): M. Smidman, A. D. Hillier, D. T. Adroja, M. R. Lees, V. K. Anand, R. P. Singh, R. I. Smith, D. M. Paul, and G. Balakrishnan The noncentrosymmetric superconductors LaPdSi3 and LaPtSi3 have been studied with magnetization, specific-heat, resistivity, and μSR measurements. These crystallize in the tetragonal BaNiSn3 structure and superconductivity is observed at Tc=2.65(5) K for LaPdSi3 and Tc=1.52(6) K for LaPtSi3. The res... [Phys. Rev. B 89, 094509] Published Mon Mar 10, 2014

Beschreibung: Author(s): Weicheng Lv, Adriana Moreo, and Elbio Dagotto Motivated by recent neutron scattering experiments in Fe-based superconductors, we study how the magnetic resonance in the superconducting state is affected by the simultaneous presence of either static or fluctuating magnetic orders using the random phase approximation. We find that for the underdo... [Phys. Rev. B 89, 104510] Published Wed Mar 12, 2014

Beschreibung: Author(s): S. Das, K. Sen, I. Marozau, M. A. Uribe-Laverde, N. Biskup, M. Varela, Y. Khaydukov, O. Soltwedel, T. Keller, M. Döbeli, C. W. Schneider, and C. Bernhard Epitaxial La1.85Sr0.15CuO4/La2/3Ca1/3MnO3 (LSCO/LCMO) superlattices on (001)-oriented LaSrAlO4 substrates have been grown with pulsed laser deposition technique. Their structural, magnetic, and superconducting properties have been determined with in situ reflection high-energy electron diffraction, ... [Phys. Rev. B 89, 094511] Published Wed Mar 12, 2014

Beschreibung: Author(s): N. Zhelev, R. G. Bennett, E. N. Smith, J. Pollanen, W. P. Halperin, and J. M. Parpia We present data for the energy dissipation factor Q−1 over a broad temperature range at various pressures of a torsion pendulum setup used to study He3 confined in a 98% open silica aerogel. Values for Q−1 above Tc are temperature independent and have weak pressure dependence. Below Tc, a deliberate... [Phys. Rev. B 89, 094513] Published Thu Mar 13, 2014

Beschreibung: Author(s): Peiwen Gao, Rong Yu, Liling Sun, Hangdong Wang, Zhen Wang, Qi Wu, Minghu Fang, Genfu Chen, Jing Guo, Chao Zhang, Dachun Gu, Huanfang Tian, Jianqi Li, Jing Liu, Yanchun Li, Xiaodong Li, Sheng Jiang, Ke Yang, Aiguo Li, Qimiao Si, and Zhongxian Zhao There is considerable interest in uncovering the physics of iron-based superconductivity from the alkaline iron selenides, a materials class containing an insulating phase (245 phase) and a superconducting (SC) phase. Due to the microstructural complexity of these superconductors, the role of the 24... [Phys. Rev. B 89, 094514] Published Thu Mar 13, 2014

Beschreibung: Author(s): T. P. Oliveira and P. D. Sacramento Topological insulators and topological superconductors display various topological phases that are characterized by different Chern numbers or by gapless edge states. In this work we show that various quantum information methods such as the von Neumann entropy, entanglement spectrum, fidelity, and f... [Phys. Rev. B 89, 094512] Published Thu Mar 13, 2014

Beschreibung: Author(s): Tom Berlijn The iron platinum arsenides Ca10(Fe1−xPtxAs)10(PtnAs8) are the first Fe-based superconductors with metallic spacer layers. Furthermore they display a large variation in their critical temperatures depending on the amount of Pt in their spacer layers: (n=3,4). To gain more insight into the role of th... [Phys. Rev. B 89, 104511] Published Thu Mar 13, 2014

Beschreibung: Author(s): Chun Fai Chan and Ming Gong The realizations of spin-orbit coupling in cold atoms lead to a burst of research activities in the searching of topological matters in ultracold atom systems. Recent theoretical predictions show that topological Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superfluids can be realized with appropriate sp... [Phys. Rev. B 89, 174501] Published Mon May 05, 2014

Beschreibung: Author(s): M. Pustilnik and K. A. Matveev We study elementary excitations of a system of one-dimensional bosons with weak contact repulsion. We show that the Gross-Pitaevskii regime, in which the excitations are the well-known Bogoliubov quasiparticles and dark solitons, does not extend to the low-energy limit. Instead, the spectra of both ... [Phys. Rev. B 89, 100504] Published Thu Mar 20, 2014

Beschreibung: Author(s): Mikio Nakahara and Tetsuo Ohmi Half-quantum vortices and ordinary vortices in a rotating thin-film superfluid 3He under a strong magnetic field are considered. It is shown that 2n+1 half-quantum vortices interpolate between n singular vortices and n+1 singular vortices as the angular velocity is changed when the external magnetic... [Phys. Rev. B 89, 104515] Published Thu Mar 20, 2014

Beschreibung: Author(s): Yuriy Makhlin, Mikhail Silaev, and G. E. Volovik We provide topological classification of possible phases with the symmetry of the planar phase of superfluid He3. Compared to the B phase [class DIII in classification of A. Altland and M. R. Zirnbauer, Phys. Rev. B 55, 1142 (1997)], it has an additional symmetry, which modifies the topology. We ana... [Phys. Rev. B 89, 174502] Published Mon May 05, 2014

Beschreibung: Author(s): R. Lusche, A. Semenov, Y. Korneeva, A. Trifonov, A. Korneev, G. Gol'tsman, and H.-W. Hübers We have studied the influence of an externally applied magnetic field on the photon and dark count rates of meander-type niobium nitride superconducting nanowire single-photon detectors. Measurements have been performed at a temperature of 4.2 K, and magnetic fields up to 250 mT have been applied pe... [Phys. Rev. B 89, 104513] Published Wed Mar 19, 2014

Beschreibung: Author(s): R. Willa, V. B. Geshkenbein, and G. Blatter We study the magnetic response of a superconducting double strip, i.e., two parallel coplanar thin strips of width 2w, thickness d≪w, and infinite length, separated by a gap of width 2s and subject to a perpendicular magnetic field H. The magnetic properties of this system are governed by the presen... [Phys. Rev. B 89, 104514] Published Wed Mar 19, 2014

Beschreibung: Author(s): Kristofer Björnson and Annica M. Black-Schaffer We provide a derivation of a spin Skyrmion number classification for two-dimensional topological superconductors constructed from ferromagnetic and Rashba spin-orbit coupled semiconductor–superconductor heterostructures. We show that in the nontrivial topological phase, characterized by a nonzero Ch... [Phys. Rev. B 89, 134518] Published Thu Apr 24, 2014

Beschreibung: Author(s): Yue Sun, Toshihiro Taen, Tatsuhiro Yamada, Sunseng Pyon, Terukazu Nishizaki, Zhixiang Shi, and Tsuyoshi Tamegai We investigated the transport properties of Fe1+yTe0.6Se0.4 single crystals with different amounts of excess Fe prepared by O2 annealing. The O2 annealing remarkably improved transport properties. In particular, a strongly nonlinear Hall resistivity was observed only in the fully annealed crystal, a... [Phys. Rev. B 89, 144512] Published Thu Apr 24, 2014

Beschreibung: Author(s): V. P. Mineev The superconducting state formed due to direct intraorbital pairing in the tetragonal multiband superconductor Sr2RuO4 has different properties than the state formed due to intraband pairing. In particular, the theory operating with direct intraorbital pairing successfully explains the Kerr rotation... [Phys. Rev. B 89, 134519] Published Fri Apr 25, 2014

Beschreibung: Author(s): F. Ahn, I. Eremin, J. Knolle, V. B. Zabolotnyy, S. V. Borisenko, B. Büchner, and A. V. Chubukov We analyze the structure of the pairing interaction and superconducting gap in LiFeAs by decomposing the pairing interaction for various kz cuts into s- and d-wave components and by studying the leading superconducting instabilities. We use the ten-orbital tight-binding model, derived from ab initio... [Phys. Rev. B 89, 144513] Published Fri Apr 25, 2014

Beschreibung: Author(s): Ka-Ming Tam, Shan-Wen Tsai, and David K. Campbell The search for realistic one-dimensional (1D) models that exhibit dominant superconducting (SC) fluctuations effects has a long history. In these 1D systems, the effects of commensurate band fillings—strongest at half-filling—and electronic repulsions typically lead to a finite charge gap and the fa... [Phys. Rev. B 89, 014513] Published Fri Jan 24, 2014

Beschreibung: Author(s): San Gillis, Juha Jäykkä, and Milorad V. Milošević Using multicomponent Ginzburg-Landau simulations, we show a plethora of vortex states possible in mesoscopic three-band superconductors. We find that mesoscopic confinement stabilizes chiral states, with nontrivial phase differences between the band condensates, as the ground state of the system. As... [Phys. Rev. B 89, 024512] Published Fri Jan 24, 2014

Beschreibung: Author(s): K. Ueno, T. Nojima, S. Yonezawa, M. Kawasaki, Y. Iwasa, and Y. Maeno We report two-dimensionality and effective thickness of the superconductivity of a SrTiO3 single-crystal surface induced by electric double-layer gating. The carrier density was tuned from 3 × 1013 to 1.1 × 1014 cm−2 by gating, where superconductivity appears with Tc of around 0.4 K. Typical two-dim... [Phys. Rev. B 89, 020508] Published Tue Jan 28, 2014

Beschreibung: Author(s): E. Stilp, A. Suter, T. Prokscha, Z. Salman, E. Morenzoni, H. Keller, C. Katzer, F. Schmidl, and M. Döbeli Adding Au nanoparticles to YBa2Cu3O7−δ thin films leads to an increase of the superconducting transition temperature Tc and the critical current density jc. While the higher jc can be understood in terms of a stronger pinning of the flux vortices at the Au nanoparticles, the enhanced Tc is still puz... [Phys. Rev. B 89, 020510] Published Tue Jan 28, 2014

Beschreibung: Author(s): Mark H. Fischer, Titus Neupert, Christian Platt, Andreas P. Schnyder, Werner Hanke, Jun Goryo, Ronny Thomale, and Manfred Sigrist Recent muon spin-rotation (μSR) measurements on SrPtAs revealed time-reversal-symmetry breaking with the onset of superconductivity [Biswas et al. , Phys. Rev. B 87 , 180503(R) (2013)PRBMDO10.1103/PhysRevB.87.180503], suggesting an unconventional superconducting state. We investigate this possibility ... [Phys. Rev. B 89, 020509] Published Tue Jan 28, 2014

Beschreibung: Author(s): T. Klein, H. Grasland, H. Cercellier, P. Toulemonde, and C. Marcenat We report on a study of the vortex creep in Fe1+δ(TexSe1−x) single crystals (x=0.5 and 0.4) down to 0.28 K (∼Tc/50) and up to μ0Ha=2T. The relaxation of the current density [J(t)] has been measured during 20 hours and the decay of J(t) can be well described by a J(t)∝[ln(t/t0)]−1/μ law. We show that... [Phys. Rev. B 89, 014514] Published Wed Jan 29, 2014

Beschreibung: Author(s): H. Mukuda, F. Engetsu, K. Yamamoto, K. T. Lai, M. Yashima, Y. Kitaoka, A. Takemori, S. Miyasaka, and S. Tajima Systematic 31P-NMR studies on LaFe(As1−xPx)(O1−yFy) with y=0.05 and 0.1 have revealed that the antiferromagnetic spin fluctuations (AFMSFs) at low energies are markedly enhanced around x=0.6 and 0.4, respectively, and as a result, Tc exhibits respective peaks at 24 and 27 K against the P substitutio... [Phys. Rev. B 89, 064511] Published Tue Feb 25, 2014

Beschreibung: Author(s): Hidetoshi Minami, Chiharu Watanabe, Kota Sato, Shunsuke Sekimoto, Takashi Yamamoto, Takanari Kashiwagi, Richard A. Klemm, and Kazuo Kadowaki From the photoluminescence of SiC microcrystals uniformly covering a rectangular mesa of the high transition temperature Tc superconductor Bi2Sr2CaCu2O8+δ, the local surface temperature T(r) was directly measured during simultaneous sub-THz emission from the N∼103 intrinsic Josephson junctions (IJJs... [Phys. Rev. B 89, 054503] Published Fri Feb 07, 2014

Beschreibung: Author(s): C. Mirri, A. Dusza, S. Bastelberger, J.-H. Chu, H.-H. Kuo, I. R. Fisher, and L. Degiorgi We use a new technique that allows in situ variation of uniaxial stress to probe the polarization dependence of the optical reflectivity of the representative underdoped iron-arsenide Ba(Fe1−xCox)2As2 through the tetragonal-to-orthorhombic structural transition and with respect to their electronic n... [Phys. Rev. B 89, 060501] Published Fri Feb 07, 2014

Beschreibung: Author(s): S. Ghannadzadeh, J. D. Wright, F. R. Foronda, S. J. Blundell, S. J. Clarke, and P. A. Goddard The upper critical field of NaFe1−xCoxAs was measured from x=0 to x=0.08, with the magnetic field applied parallel (Hc2∥) and normal (Hc2⊥) to the planes. The data were fitted using one-band and two-band models. The orbital and paramagnetic components of the upper critical field were extracted for H... [Phys. Rev. B 89, 054502] Published Fri Feb 07, 2014

Beschreibung: Author(s): Juha M. Kreula, Miikka O. J. Heikkinen, Francesco Massel, and Päivi Törmä Combining the Josephson effect with magnetism, or spin dependence in general, creates novel physical phenomena. The spin-asymmetric Josephson effect is a predicted phenomenon where a spin-dependent potential applied across a Josephson junction induces a spin-polarized Josephson current. Here, we pro... [Phys. Rev. B 89, 064502] Published Tue Feb 11, 2014

Beschreibung: Author(s): F. S. Bergeret and F. Giazotto We investigate the behavior of a Josephson junction consisting of a ferromagnetic insulator-superconductor (FI-S) bilayer tunnel coupled to a superconducting electrode. We show that the Josephson coupling in the structure is strengthened by the presence of the spin-splitting field induced in the FI-... [Phys. Rev. B 89, 054505] Published Tue Feb 11, 2014

Beschreibung: Author(s): Wenhao Zhang, Zhi Li, Fangsen Li, Huimin Zhang, Junping Peng, Chenjia Tang, Qingyan Wang, Ke He, Xi Chen, Lili Wang, Xucun Ma, and Qi-Kun Xue We prepare single-unit-cell FeSe films on insulating SrTiO3 substrates by molecular beam epitaxy and investigate the evolution of their superconducting properties with annealing by in situ scanning tunneling microscopy and scanning tunneling spectroscopy and ex situ transport measurements. We find t... [Phys. Rev. B 89, 060506] Published Tue Feb 25, 2014

Beschreibung: Author(s): A. A. Bespalov, A. S. Mel'nikov, and A. I. Buzdin In systems combining type-II superconductivity and magnetism the nonstationary magnetic field of moving Abrikosov vortices may excite spin waves, or magnons. This effect leads to the appearance of an additional damping force acting on the vortices. By solving the London and Landau-Lifshitz-Gilbert e... [Phys. Rev. B 89, 054516] Published Wed Feb 26, 2014

Beschreibung: Author(s): Jacob Schmiedt, P. M. R. Brydon, and Carsten Timm Some of the iron pnictides show coexisting superconductivity and spin-density-wave order. We study the superconducting pairing instability in the spin-density-wave phase. Assuming that the pairing interaction is due to spin fluctuations, we calculate the effective pairing interactions in the singlet... [Phys. Rev. B 89, 054515] Published Wed Feb 26, 2014

Beschreibung: Author(s): Pedro Ribeiro and Antonio M. García-García Even in the absence of Coulomb interactions, phase fluctuations induced by quantum size effects become increasingly important in superconducting nanostructures as the mean level spacing becomes comparable with the bulk superconducting gap. Here we study the role of these fluctuations, termed “quantu... [Phys. Rev. B 89, 064513] Published Wed Feb 26, 2014

Beschreibung: Author(s): Chuck-Hou Yee and Gabriel Kotliar Chemical substitution, combined with strain, allows the charge-transfer energy in hole-doped cuprates to be broadly tuned. We theoretically characterize the structural and electronic properties of the family of compounds R2CuO2S2, constructed by sulfur replacement of the apical oxygens and rare-eart... [Phys. Rev. B 89, 094517] Published Mon Mar 24, 2014

Beschreibung: Author(s): Yong Wang and Fu-Chun Zhang Motivated by recent development in time-resolved angle-resolved photoemission spectroscopy (trARPES) for d-wave superconductors, we analyze the nonequilibrium relaxation dynamics of the laser pulse excited sample within the scenario of a two-temperature model. The main features reported in the trARP... [Phys. Rev. B 89, 094519] Published Tue Mar 25, 2014

Beschreibung: Author(s): Yang Yang, Wan-Sheng Wang, Jin-Guo Liu, Hua Chen, Jian-Hui Dai, and Qiang-Hua Wang Using the functional renormalization group we investigated possible superconductivity in doped Sr2IrO4. In the electron-doped case, a dx2−y2*-wave superconducting phase is found in a narrow doping region. The pairing is driven by spin fluctuations within the single conduction band. In contrast, for ... [Phys. Rev. B 89, 094518] Published Tue Mar 25, 2014

Beschreibung: Author(s): Shin-ichi Fujimori, Ikuto Kawasaki, Akira Yasui, Yukiharu Takeda, Tetsuo Okane, Yuji Saitoh, Atsushi Fujimori, Hiroshi Yamagami, Yoshinori Haga, Etsuji Yamamoto, and Yoshichika Ōnuki The electronic structure of the ferromagnetic superconductor URhGe in the paramagnetic phase has been studied by angle-resolved photoelectron spectroscopy using soft x rays (hν=595–700 eV). Dispersive bands with large contributions from U 5f states were observed in the ARPES spectra and form Fermi s... [Phys. Rev. B 89, 104518] Published Wed Mar 26, 2014

Beschreibung: Author(s): Xiaofeng Xu, W. H. Jiao, N. Zhou, Y. K. Li, B. Chen, C. Cao, Jianhui Dai, A. F. Bangura, and Guanghan Cao Electronic nematics, an electron orientational order which breaks the underlying rotational symmetry, were observed in iron pnictide superconductors several years after their discovery. However, the universality of the doping dependence of this phase and its relation to other symmetry-breaking order... [Phys. Rev. B 89, 104517] Published Wed Mar 26, 2014

Beschreibung: Author(s): C. N. Kuo, H. F. Liu, C. S. Lue, L. M. Wang, C. C. Chen, and Y. K. Kuo In order to assess the phase transition nature in Sr3Ir4Sn13, we have carried out the electrical resistivity, Hall coefficient, Seebeck coefficient, thermal conductivity, specific heat, and 119Sn nuclear magnetic resonance (NMR) measurements, mainly focusing on the signatures around the phase transi... [Phys. Rev. B 89, 094520] Published Thu Mar 27, 2014

Beschreibung: Author(s): Kuei Sun, Ching-Kai Chiu, Hsiang-Hsuan Hung, and Jiansheng Wu We study spin-half fermions in a one-dimensional extended Hubbard chain at low filling. We identify three triplet and one singlet pairing channels in the system, which are independently tunable as a function of nearest-neighbor charge and spin interactions. In a large-size system with translational ... [Phys. Rev. B 89, 104519] Published Thu Mar 27, 2014