arXiv subjects

Alexander M. Finkel'stein

Publications and source records attributed to Alexander M. Finkel'stein.

26 records · Page 2Linked to original sources

arXiv2001

Dilute electron gas near the metal-insulator transition in two dimensions

In recent years systematic experimental studies of the temperature dependence of the resistivity in a variety of dilute, ultra clean two dimensional electron/hole systems have revived the fundamental question of localization or, alternatively, the existence of a metal-insulator transition in the presence of strong electron-electron interactions in two dimensions. We argue that under the extreme conditions of ultra clean systems not only is the electron-electron interaction very strong but the role of other system specific properties are also enhanced. In particular, we emphasize the role of valleys in determining the transport properties of the dilute electron gas in silicon inversion layers (Si-MOSFETs). It is shown that for a high quality sample the temperature behavior of the resistivity in the region close to the critical region of the metal-insulator transition is well described by a renormalization group analysis of the interplay of interaction and disorder if the electron band is assumed to have two distinct valleys. The decrease in the resistivity up to five times has been captured in the correct temperature interval by this analysis, without involving any adjustable parameters. The considerable variance in the data obtained from different Si-MOSFET samples is attributed to the sample dependent scattering rate across the two valleys, presenting thereby with a possible explanation for the absence of universal behavior in Si-MOSFET samples of different quality.

cond-mat.dis-nn↗

arXiv1999

Suppression of $\bbox{T_c}$ in superconducting amorphous wires

The suppression of the mean field temperature of the superconducting transition, $T_c$, in homogeneous amorphous wires is studied. We develop a theory that gives $T_c$ in situations when the dynamically enhanced Coulomb repulsion competes with the contact attraction. The theory accurately describes recent experiments on $T_c$--suppression in superconducting wires, after a procedure that minimizes the role of nonuniversal mechanisms influencing $T_c$ is applied.

cond-mat.supr-con↗

arXiv1997

A Single Impurity in Tomonaga-Luttinger Liquids

The problem of a single impurity in one dimensional Tomonaga-Luttinger liquids with a repulsive electron-electron interaction is discussed. We find that the renormalization group flow diagram for the parameters characterizing the impurity is rather complex. Apart from the fixed points corresponding to two weakly connected semi-infinite wires, the flow diagram contains additional fixed points which control the low temperature physics when the bare potential of the impurity is not strong.

cond-mat↗

arXiv1997

Reply to the Comment on "Enhancement of the Tunneling Density of States in Tomonaga-Luttinger Liquids"

In their comment Fabrizio and Gogolin dispute our result of the enhancement of the tunneling density of states in a Tomonaga-Luttinger liquid at the location of a backward scattering defect [Phys. Rev. Lett. 76, 4230(1996); cond-mat/9601020]. They state that the anticommutativity of the fermion operators of the left and right moving electrons was not considered properly in the Letter. We show in the Reply that the result of the Letter can be reproduced following the Comment when its calculations are performed correctly. This clearly indicates that the question about the anticommutation relations was raised by Fabrizio and Gogolin without serious grounds.

cond-mat↗

arXiv1996

DC--Transport in Quantum Wires

The influence of electron--electron interaction on two terminal DC conductance of one--dimensional quantum wires is studied. A cancelation between the effect of the electron--electron interaction on the current and on the external electric field is the reason for the universal value, $e^2/2π\hbar $ per mode, of the DC conductance of a clean wire. The effect of the renormalization of the electric field on the DC conductance in the presence of an interplay between the electron--electron interaction and backward scattering due to an impurity is considered.

cond-mat↗

arXiv1996

Resonance in One--Dimensional Fermi--Edge Singularity

The problem of the Fermi--edge singularity in a one--dimensional Tomonaga--Luttinger liquid is reconsidered. The backward scattering of the conduction band electrons on the impurity--like hole in the valence band is analyzed by mapping the problem onto a Coulomb gas theory. For the case when the electron--electron interaction is repulsive the obtained exponent of the one--dimensional Fermi--edge singularity appears to be different from the exponent found in the previous studies. It is shown that the infrared physics of the Fermi--edge singularity in the presence of backward scattering and electron--electron repulsion resembles the physics of the Kondo problem.

cond-mat↗

arXiv1996

Enhancement of the tunneling density of states in Tomonaga--Luttinger Liquids

We have calculated the tunneling density of states (DOS) at the location of a backward scattering defect for quantum wires and for edge state electrons in quantum Hall systems. A singular enhancement of the DOS arises as a result of the combined effect of multiple backward scattering together with a repulsive electron---electron interaction.

cond-mat↗

arXiv1995

Inter-Edge interaction in the Quantum Hall Effect

We consider effects of the interaction between electrons drifting along the opposite sides of a narrow sample under the conditions of the quantum Hall effect. A spatial variation of this interaction leads to backward scattering of collective excitations propagating along the edges. Experiments on propagation of the edge modes in samples with constrictions may give information about the strength of the inter-edge electron interaction in the quantum Hall regime.

cond-mat↗