Abstract
A small-capacitance normal tunnel deviates significantly from equilibrium because each tunneling event turns the junction voltage almost upside-down. If such a sudden perturbation occurs locally, Fermi liquid theory guarantees that infinitely many electron-hole pairs should be created near the Fermi surface. It is predicted that such an infrared-divergent shake-up combined with the electromagnetic environment leads to subgap conductance anomalies for two categories of junctions. For symmetric junctions whose electrodes have the same electronic properties, a nonvanishing subgap conductance is shown to be inevitable even if the environmental impedance is infinite. This effect smoothes the current-voltage (I–V) characteristic and shifts the Coulomb offset extrapolated back from the high-voltage part of theI–V curve. For asymmetric junctions, whose electrodes have different electronic affinities, tunneling conductance is enhanced in one direction and suppressed in the other; that is, the junctions exhibit a diode effect. In particular, when the tunneling resistance is much smaller than the resistance quantum and the current flows in the favorable direction, a strong tendency towards establishing phase coherence is shown to emerge, as in Josephson junctions, resulting in infinite differential conductance at zero bias voltage.
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See, for instance, Averin, D.V., Likharev, K.K.: In: Mesoscopic phenomena in solids. Altshuler, B.L., Lee, P.A., Webb, R.A. (eds.), p. 173, Amsterdam: Elsevier 1991
Schön G., Zaikin, A.D.: Phys. Rep.198, 237 (1990)
Nazarov, Yu.V.: Sov. Phys. JETP68, 561 (1989)
Devoret, M.H., Esteve, D., Grabert, H., Ingold, G.-L., Pothier, H., Urbina, C.: Phys. Rev. Lett.64, 1824 (1990)
Girvin, S.M., Glazman, L.I., Jonson, M., Penn, D.R., Stiles, M.D.: Phys. Rev. Lett.64, 3183 (1990)
Guinea, F., Schön, G.: Europhys. Lett.1, 585 (1986)
For reviews, see, Hauge, E.H., Støveng, J.A.: Rev. Mod. Phys.61, 917 (1989); Büttiker, M.: In Electronic properties of multilayer and low-dimensional semiconductors structures. Chamberlain, J.M. et al. (eds.), p. 297. New York: Plenum Press 1990
Caldeira, A.O., Leggett, A.J.: Phys. Rev. Lett.46, 211 (1981); Ann. Phys. (N.Y.)149, 374 (1983)
Ueda, M., Kurihara, S.: NTT Basic Research Laboratories preprint (1991); In: Macroscopic quantum phenomena. Clark T.D., Prance, H., Prance, R.J., Spiller, T.P. (eds.), p. 143. Singapore: World Scientific 1990
Nozières, P., Dominics, C.T. De: Phys. Rev.178, 1097 (1969)
Anderson, P.W.: Phys. Rev. Lett.18, 1049, (1967); Phys. Rev.164, 352 (1967)
Averin, D.V., Odintsov, A.A.: Phys. Lett. A140, 251 (1989)
Averin, D.V., Nazarov, Yu.V.: In: Grabert, H., Devoret, M.H. (eds.): Proceedings of the NATO ASI onSingle Charge Tunneling, Les Houches, March 1991. New York: Plenum Press 1992
Geerligs, L.J., Averin, D.V., Mooij, J.E.: Phys. Rev. Lett.65, 3037, (1980)
Panyukov, S.V., Zaikin, A.D.: (unpublished)
Kostterlitz, J.M.: Phys. Rev. Lett.37, 1577 (1976)
Cleland, A.N., Schmidt, J.M., Clarke, J.: Phys. Rev. Lett.64, 1565 (1990)
Delsing, P.: In: Grabert, H., Devoret, M.H. (eds.): Proceedings of the NATO ASI onSingle Charge Tunneling, Les Houches, March 1991. New York, Plenum Press 1992
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Ueda, M., Guinea, F. Conductance anomalies of small tunnel junctions inside the Coulomb gap. Z. Physik B - Condensed Matter 85, 413–419 (1991). https://doi.org/10.1007/BF01307638
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DOI: https://doi.org/10.1007/BF01307638