APhMS: EAS Trailblazers Department Seminar

Abstract:

Random quantum vacuum fluctuations exist everywhere, and they lead to the Casimir interaction between macroscopic bodies. Phonons normally can not transport in vacuum except utilizing Casimir interactions. In the talk, I will present the first experimental demonstration of quantum vacuum-mediated non-reciprocal phonon energy transfer between two micromechanical oscillation. This work reveals a new mechanism for regulating phonon transfer in vacuum. Besides, I will introduce the first observation of three-body Casimir interactions. In the second part of the talk, I will introduce the scheme towards probing phonons emitted from silicon-vacancy (SiV) color centers in diamonds. Phonons in solid-state quantum systems attract a lot of interest for the potential of encoding chip-scale qubits. The negatively charged SiV in diamond has a remarkably high strain susceptibility, and its spin levels can be coherently driven by resonant surface acoustic wave (SAW) so it is one of the best candidates for realizing phononic quantum devices. I will talk about the experimental efforts in enhancing spin-phonon interaction and the scheme of probing single phonons from a single SiV.

More about the Speaker:

Zhujing Xu received her B.S. in Physics from University of Science and Technology of China in 2016. After that, she joined Prof. Tongcang Li's group at Purdue University and received her Ph.D. in Physics in 2022. During her Ph.D., she has worked on optomechanics and solid-state spins. Her thesis work focused on building Casimir devices and realizing quantum vacuum mediated energy transfer between mechanical oscillators. Currently, she is a Harvard Quantum Initiative (HQI) postdoctoral fellow working in Prof. Marko Loncar's group at Harvard University. She is working on probing and controlling spin-phonon interactions in diamonds.