Path-integral approach to the scattering theory of quantum transport

Article

关键词: RANDOM-MATRIX THEORY;    HIGH-GRADIENT OPERATORS;    NONLINEAR SIGMA-MODEL;    DISORDERED WIRES;    TRANSMISSION EIGENVALUES;    MESOSCOPIC FLUCTUATIONS;    MACROSCOPIC APPROACH;    CONDUCTANCE FLUCTUATIONS;    ANOMALOUS DIMENSIONS;    FOURIER-ANALYSIS;   

DOI  :  10.1103/PhysRevB.57.12448

来源: SCIE

【 摘 要 】

The scattering theory of quantum transport relates transport properties of disordered mesoscopic conductors to their transfer matrix T. We introduce an approach to the statistics of transport quantities which expresses the probability distribution of T as a path integral. The path integal is derived for a model of conductors with broken time-reversal invariance in arbitrary dimensions. It is applied to the Dorokhov-Mello-Pereyra-Kumar (DMPK) equation which describes quasi-one-dimensional wires. We use the equivalent channel model whose probability distribution for the eigenvalues of TTdagger is equivalent to the DMPK equation independent of the values of the forward scattering mean free paths. We find that infinitely strong forward scattering corresponds to diffusion on the coset space of the transfer-matrix group. It is shown that the saddle-point of the path integral corresponds to ballistic conductors with large conductances. We solve the saddle-paint equation and recover random-matrix theory from the saddle-point approximation to the path integral.

【 授权许可】

Free