Transmission phase lapses through a quantum dot in a strong magnetic field

TL;DR

This paper investigates how strong magnetic fields influence the transmission phase behavior in quantum dots, revealing that phase lapses can occur on resonance as a genuine interaction effect, and are robust against temperature effects.

Contribution

It demonstrates that in strong magnetic fields, phase lapses are a genuine interaction effect and can occur on resonance, differing from the behavior without magnetic fields.

Findings

Phase lapses occur on resonance in strong magnetic fields.

Phase lapses are robust against finite temperature broadening.

Interaction effects are key to phase lapses in magnetic fields.

Abstract

The phase of the transmission amplitude through a mesoscopic system contains information about the system's quantum mechanical state and excitations thereof. In the absence of an external magnetic field, abrupt phase lapses occur between transmission resonances of quantum dots and can be related to the signs of tunneling matrix elements. They are smeared at finite temperatures. By contrast, we show here that in the presence of a strong magnetic field, phase lapses represent a genuine interaction effect and may occur also on resonance. For some realistic parameter range these phase lapses are robust against finite temperature broadening.