Interaction-Induced Resonance in Conductance and Thermopower of Quantum Wires

TL;DR

This paper explores how electron-electron interactions induce resonances in conductance and thermopower of quantum wires, revealing characteristic signatures and the influence of magnetic fields on these phenomena.

Contribution

It provides a detailed analysis of interaction-induced resonances in multi-channel quantum wires, including the effects of magnetic fields and temperature on conductance and thermopower.

Findings

Resonances cause peaks in conductance and thermopower at specific Fermi energies.

Resonance width is determined by temperature and decays exponentially away from resonance.

Magnetic fields cause four-fold splitting of the resonance, serving as a signature of interaction effects.

Abstract

We study the effect of electron-electron interaction on the transport properties of short clean quantum wires adiabatically connected to reservoirs. Interactions lead to resonances in a multi-channel wire at particular values of the Fermi energy. We investigate in detail the resonance in a two-channel wire. The (negative) conductance correction peaks at the resonance, and decays exponentially as the Fermi energy is tuned away; the resonance width being given by the temperature. Likewise, the thermopower shows a characteristic structure, which is surprisingly well approximated by the so-called Mott formula. Finally, four-fold splitting of the resonance in a magnetic field provides a unique signature of the effect.