Single electron-phonon interaction in a suspended quantum dot phonon cavity

TL;DR

This study demonstrates phonon blockade in a suspended quantum dot cavity, where localized phonon modes suppress electron tunneling, revealing new insights into electron-phonon interactions at the nanoscale.

Contribution

The paper reports the first observation of phonon blockade in a suspended quantum dot cavity, highlighting the role of localized phonon modes in electron transport suppression.

Findings

Complete suppression of electron tunneling around zero bias.

Energy gap formation due to localized phonon mode excitation.

Lifting of phonon blockade at specific magnetic fields.

Abstract

An electron-phonon cavity consisting of a quantum dot embedded in a free-standing GaAs/AlGaAs membrane is characterized in Coulomb blockade measurements at low temperatures. We find a complete suppression of single electron tunneling around zero bias leading to the formation of an energy gap in the transport spectrum. The observed effect is induced by the excitation of a localized phonon mode confined in the cavity. This phonon blockade of transport is lifted at magnetic fields where higher electronic states with nonzero angular momentum are brought into resonance with the phonon energy.