Quantum Transport and Interactions in Mesoscopic Conductors at milli-Kelvin Temperatures
This research addresses experimentally several inter-related fundamental problems of electron transport in low-dimensional conductors:
- hopping conductivity in the systems with a large localization length
- origin of a strong orbital magnetoresistance observed for 2d conductors in the hopping regime and direct measurements of the localization length
- mechanism of hopping conductivity in low-dimensional conductors with a large localization length (electron-assisted hopping versus phonon-assisted)
- crossover from weak to strong localization in low-dimensional conductors
- interference effects in the magnetoresistance of multi-connected samples in the hopping regime.
- dephasing in low-dimensional conductors at ultra-low temperatures
The problem of intrinsic and extrinsic limitations on the dephasing rate in low-dimensional conductors is crucial for many areas of condensed matter physics, as well as for the solid state implementation of quantum computing. Further progress in this field is associated with dephasing measurements at milli-Kelvin temperatures. Our experiments are aimed at better understanding of dephasing mechanisms (including the dephasing by external high-frequency electromagnetic noise), and extending the temperature range of dephasing measurements in 1d and 2d systems down to T ~ 20 mK by means of thorough suppression of external noise (elimination of noise-induced dephasing), and optimization of electron-phonon interaction (elimination of hot-electron effects).
Selected Publications:
Wei Jian, S. Pereverzev, and M. E. Gershenson, “Microwave-induced dephasing in one-dimensional metal wires, Phys. Rev. Lett. 96, 086801 (2006).
M. E. Gershenson, Low-temperature dephasing in disordered conductors: experimental aspects, Annalen der Physik 8, 559-568 (1999).
Yu. B. Khavin, M. E. Gershenson, and A. L. Bogdanov, Strong localization of electrons in quasi-one-dimensional conductors, Phys.Rev. B 58, 8009-8019 (1998).
B. L. Altshuler, M. E. Gershenson, and I. L. Aleiner, Phase relaxation of electrons in disordered conductors, Physica E 3, 58-68 (1998).
Yu. B. Khavin, M. E. Gershenson, and A. L. Bogdanov, Decoherence and the Thouless crossover in one-dimensional conductors, Phys. Rev. Lett. 81, 1066-1069 (1998).
M. E. Gershenson, Yu. B. Khavin, A. G. Mikhalchuk, H. M. Bozler, and A. L. Bogdanov, Crossover from weak to strong localization in quasi-one-dimensional conductors, Phys. Rev. Lett. 79, 725-728 (1997).