“Engineering sound waves and vibrations in multi-mode nanomechanical systems”

Dr. Jin Woong Cha
Quantum Technology Institute, KRISS

Jun. 11 (Fri.), 02:30 PM
Online seminar
https://kaist.zoom.us/j/89283252628
회의 ID: 892 8325 2628
암호: 916514

Abstract:
Nanoscale mechanical systems provide versatile physical interfaces with their ability to interact with various physical states, for example, electromagnetic fields (e.g., microwaves and optical light) and quantum states (e.g., spins and electrons). Therefore, engineering nanoscale sound waves and vibrations in nanomechanical systems is essential for a wide range of applications in sensing and information processing both in the classical and quantum regimes. My talk will focus on two different nanomechanical platforms I have recently worked on. In the first part of my talk, I will discuss a unique nanomechanical platform called nanomechanical lattices which enable electrically tunable phonon propagation dynamics [1] and topologically protected phonon transport [2] at MHz frequencies. This platform consists of arrays of mechanically coupled, free-standing silicon-nitride nanomechanical membranes that support propagating flexural elastic waves. For the second part of my talk, I will describe our recent studies on the cavity electromechanics in a superconducting nanoelectromechanical resonator implementing superconducting niobium [3]. This system demonstrates various optomechanical phenomena arising from the interaction of nanomechanical motions and microwave fields (e.g., phonon cooling and amplification, optomechanically induced reflection) and can be used in various applications such as quantum transducers. I will then conclude my talk by briefly describing our ongoing work at KRISS.

Reference:
[1] J. Cha, et al. Nature Nanotechnology 13, 1016-1020 (2018)
[2] J. Cha, et al. Nature 564, 229-233 (2018)
[3] J. Cha, et al. Nano Letters 21, 1800-1806 (2021)