Nanomechanical Microwave Bolometry with Semiconducting Nanowires

Abstract

Microwave loss of a semiconducting nanowire implemented in a cavity electromechanical system enables bolometric-microwave-power measurements at millikelvin temperatures. This hybrid system consists of a superconducting microwave cavity capacitively coupled to a suspended InAs nanowire. As a constant voltage is applied across a vacuum gap between the nanowire and the bottom electrode, the nanowire resistance embedded in the microwave resonator follows its own mechanical vibration. The mechanically modulated resistance of the nanowire contributes to microwave sidebands exhibiting its mechanical resonance. The presence of this resistive component provides the device with enhanced sensitivity to microwave dissipation. This dissipation localized at the nanowire results in a temperature increase, producing a frequency shift of the mechanical resonance sensitive to the microwave power. We employ a circuit model to demonstrate that semiconducting nanowires provide optimal resistances for the nanomechanical microwave bolometry. Our technique could benefit precision microwave measurements in quantum-device research. ？ 2021 American Physical Society.