Development in the Scattering Matrix Theory: From Spin-Orbit-Coupling Affected Shot Noise to Quantum Pumping

TL;DR

This paper reviews the development of scattering matrix theory, focusing on spin-orbit-coupling effects on shot noise and quantum pumping, highlighting recent theoretical and experimental advances in mesoscopic conductors.

Contribution

It provides a comprehensive pedagogical overview of scattering theory and introduces recent developments in spin-dependent shot noise and quantum pumping models.

Findings

Observation of shot noise suppression below Fano factor 0.5 due to spin effects

Development of Floquet scattering theory for quantum pumping

Experimental evidence of spin-dependent shot noise effects

Abstract

The review chapter starts by a pedagogical introduction to the general concept of the scattering theory: from the fundamental wave-function picture to the second-quantization language, with the aim to clear possible ambiguity in conventional textbooks. Recent progress in applying the method to current fluctuations and oscillating-parameter driven quantum pumping processes is presented with inclusion of contributions by B\"{u}ttiker, Brouwer, Moskalets, Zhu, etc. In particular, the spin-orbit-coupling affected shot noise can be dealt with by taking into account the spin-dependent scattering processes. A large shot noise suppression with the Fano factor below 0.5 observed experimentally can be illustrated by effective repulsion between electrons with antiparallel spin induced by the Dresselhaus spin-orbit coupling effect. A Floquet scattering theory for quantum-mechanical pumping in mesoscopic conductors is developed by Moskalets et al., which gives a general picture of quantum pumping phenomenon, from adiabatic to non-adiabatic and from weak pumping to strong pumping.