Resonant driving of a single photon emitter embedded in a mechanical oscillator

TL;DR

This paper demonstrates resonant driving of a quantum dot embedded in a mechanical resonator, showing strong coupling and potential for quantum-limited displacement measurements at cryogenic temperatures.

Contribution

It introduces an intrinsic strain-based coupling in a monolithic semiconductor system, achieving high cooperativity and approaching the Heisenberg limit in displacement sensing.

Findings

Observation of mechanical Brownian motion at 4K via resonance fluorescence

Identification of a mechanical mode with cooperativity > 1

Analytical demonstration of Heisenberg limit reach with quantum dots

Abstract

Coupling a microscopic mechanical resonator to a nano-scale quantum system enables control of the mechanical resonator via the quantum system, and vice versa. The coupling is usually achieved through functionalization of the mechanical resonator but this results in additional mass and dissipation channels. An alternative is an intrinsic coupling based on strain. We employ here a monolithic semiconductor system. The nano-scale quantum system is a quantum dot; the mechanical resonator a microscopic trumpet which simultaneously optimizes the mechanical and photonic properties. The quantum dot transition is driven resonantly. Via the resonance fluorescence, we observe mechanical Brownian motion even at 4K, and demonstrate a coupling to mechanical modes of different types. We identify a mechanical mode with a cooperativity larger than one. We show analytically that the Heisenberg limit on displacement measurement can be reached with an embedded two-level system in the case of a transform-limited optical emitter with perfect photon detection. We argue that operation close to the Heisenberg limit is achievable with state-of-the-art quantum dot devices.