Photon-assisted-tunneling in a coupled double quantum dot out of thermal equilibrium

TL;DR

This paper reports on photon-assisted tunneling experiments in a GaAs double quantum dot under high microwave power, revealing multi-photon absorption, LZS interference signatures, and charge relaxation times in a non-equilibrium state.

Contribution

It demonstrates photon-assisted tunneling with up to 14 photons and observes LZS interference in a non-equilibrium quantum dot system, expanding understanding of quantum coherence under high excitation.

Findings

Photon absorption of up to 14 photons observed.

LZS interference signatures found in non-equilibrium conditions.

Charge relaxation time T_1 ~ 8 ns measured.

Abstract

We perform photon-assisted-tunneling (PAT) experiments on a GaAs double quantum dot device under high microwave excitation power. Photon-assisted absorption of up to 14 photons is observed, when electron temperature (>1K) are far above the lattice temperature. Signatures of Landau-Zener-St\"uckelberg (LZS) interference are found even in this non-equilibrium PAT spectrum. In addition, the charge state relaxation time T_1~8ns measured in this out of thermal equilibrium double quantum dot is in agreement with other previous reports.