Variable-range cotunneling and conductivity of a granular metal
The Efros-Shklovskii (E-S) law for the conductivity of granular metals is interpreted as a result of a variable-range cotunneling process. The cotunneling between distant resonant grains is predominantly elastic at low T ≤ Tc, while it is inelastic (i.e., accompanied by creation of electron-hole pairs on a string of intermediate non-resonant grains) at T ≥ Tc. The corresponding E-S temperature TES, in the latter case, is slightly (logarithmically) T dependent. The magnetoresistance in the two cases is different: it may be relatively strong and negative at T≪Tc , while, at T > Tc, it is suppressed due to inelastic processes, which destroy the interference.
PACS numbers73.23.Hk 73.43.Qt 73.63.−b
Unable to display preview. Download preview PDF.
- 5.B. I. Shklovskii and A. L. Éfros, Electronic Properties of Doped Semiconductors (Nauka, Moscow, 1979; Springer, New York, 1984).Google Scholar
- 6.J. Zhang and B. I. Shklovskii, Phys. Rev. B 70, 115317 (2004).Google Scholar
- 9.M. V. Feigel’man, A. S. Ioselevich, and M. A. Skvortsov, Phys. Rev. Lett. 93, 136403 (2004).Google Scholar
- 12.H. L. Zhao, B. Z. Spivak, M. P. Celfand, and S. Feng, Phys. Rev. B 44, 10760 (1991).Google Scholar
- 13.B. I. Shklovskii and B. Z. Spivak, in Hopping Transport in Solids, Ed. by M. Pollak and B. Shklovskii (Elsevier, Amsterdam, 1991), p. 271.Google Scholar
- 14.L. I. Glazman and M. Pustilnik, cond-mat/0501007.Google Scholar
- 15.D. V. Averin and K. K. Likharev, in Mesoscopic Phenomena in Solids, Ed. by B. L. Altshuler, P. A. Lee, and R. A. Webb (Elsevier, Amsterdam, 1991).Google Scholar
- 18.I. S. Beloborodov, A. V. Lopatin, V. M. Vinokur, and V. I. Kozub, cond-mat/0501094.Google Scholar