Electron Bunching in Transport Through Quantum Dots in High Magnetic Field

TL;DR

This study uses shot noise measurements in a quantum dot under high magnetic field to reveal electron bunching phenomena, which are absent without the magnetic field, indicating magnetic field-induced correlations.

Contribution

It demonstrates magnetic field-induced electron bunching in quantum dots through shot noise analysis, revealing new correlation effects not observed at zero magnetic field.

Findings

Shot noise at conductance peaks was nine times higher than expected.

Electron bunching occurs only under high magnetic fields.

Enhanced noise suggests correlations mediated by weakly coupled levels or excited states.

Abstract

Shot noise measurements provide information on particles' charge and their correlations. We report on shot noise measurements in a ubiquitous quantum dot under a quantized magnetic field. The measured noise at the peaks of a sequence of conductance resonances was some nine times higher than expected; suggesting bunching of electrons as they traverse through the dot. This enhancement might be mediated by an additional weakly coupled level to the leads or an excited state. Note that in the absence of magnetic filed no bunching had been observed.