Near-field cavity optomechanical coupling in a compound semiconductor nanowire

TL;DR

This paper demonstrates near-field coupling between a silica microsphere cavity and an epitaxially grown InP/InAs nanowire, enabling detailed mechanical motion probing and control, paving the way for advanced quantum technologies.

Contribution

It introduces a novel near-field cavity optomechanical coupling method with a compound semiconductor nanowire, overcoming size mismatch challenges.

Findings

Achieved evanescent optomechanical coupling between microsphere cavity and nanowire.

Enabled tuning of nanowire resonance frequency, linewidth, and nonlinearity.

Demonstrated potential for quantum metrology and information processing.

Abstract

A III-V compound semiconductor nanowire is an attractive material for a novel hybrid quantum interface that interconnects photons, electrons, and phonons through a wavelength-tunable quantum structure embedded in its free-standing structure. In such a nanomechanical element, however, a challenge is how to detect and manipulate a small number of phonons via its tiny mechanical motion. A solution would be to couple an optical cavity to a nanowire by introducing the ``cavity optomechanics'' framework, but the typical size difference between them becomes a barrier to achieving this. Here, we demonstrate near-field coupling of a silica microsphere cavity and an epitaxially grown InP/InAs free-standing nanowire. The evanescent optomechanical coupling enables not only fine probing of the mechanical motion by balanced homodyne interferometry but also tuning of the resonance frequency, linewidth, Duffing nonlinearity, and vibration axis in the nanowire. Combining this cavity optomechanics with epitaxial nanowire engineering opens the way to novel quantum metrology and information processing.