날짜: 2021년 9월 8일 (수)  15:00 ~ 17:00

주제: SCQC 정기 세미나

장소: Zoom 회의

 - 초청연사 -

주정진(ETRI) 15:00~16:00

서준호(KRISS) 16:00~17:00

"Quantum Electromechanical Devices and Their Applications"

 Mechanical resonators have been employed as precision sensors in a diverse range of physical measurements. These mechanical devices reached the quantum regime recently as they demonstrate operations near ground states and coherent coupling to other quantum systems. In this talk, I will discuss two of our recent experiments in the course of developing such quantum electro-mechanical systems[1,2]. First, we demonstrate a cavity electromechanical device based on niobium with significant improvements in operating conditions of temperature and magnetic field compared to the conventional aluminum devices. The device manifests optomechanical effects in the microwave domain up to 4 Kelvin and 0.9 Tesla, and it could be utilized for the quantum-limited sensing in magnetic environments. Second, a nanomechanical resonance technique realizes microwave bolometry at millikelvin temperatures. We employ a suspended InAs nanowire as a part of superconducting microwave resonator such that its nanomechanical resonance frequency becomes sensitive to the microwave power absorbed by the nanowire, constituting a microwave bolometer with picowatt resolution. Our work illustrate routes to harness the versatility of nanomechanical resonators for the purpose of connecting disparate components to build quantum hybrid systems with multitasking capabilities.

[1] J. Cha et.al., Nano Lett. 21, 1800 (2021).

[2] J. Kim et.al., Phys. Rev. Applied 15, 034075 (2021).