A Hybrid (Al)GaAs-LiNbO$_3$ Surface Acoustic Wave Resonator for Cavity Quantum Dot Optomechanics

TL;DR

This paper presents a heterointegrated hybrid device combining (Al)GaAs quantum dots with a LiNbO$_3$ surface acoustic wave resonator, achieving high quality factors and strong optomechanical coupling suitable for quantum applications.

Contribution

It introduces a novel heterointegration of quantum dots with a surface acoustic wave resonator, demonstrating high Q-factors and optomechanical coupling at elevated temperatures.

Findings

Achieved Q>4000 at 300 MHz

Q×f>10^{12} ensures low decoherence at T>50K

Observed frequency and position dependent coupling

Abstract

A hybrid device comprising a (Al)GaAs quantum dot heterostructure and a LiNbO$_3$ surface acoustic wave resonator is fabricated by heterointegration. High acoustic quality factors $Q>4000$ are demonstrated for an operation frequency $f\approx 300$ MHz. The measured large quality factor-frequency products $Q\times f>10^{12}$ ensures the suppression of decoherence due to thermal noise for temperatures exceeding $T>50\,\mathrm{K}$. Frequency and position dependent optomechanical coupling of single quantum dots and the resonator modes is observed.