School of Physics · Zhejiang University

X2 -Hybrid Quantum System Lab (website under construction)

The interplay between light and mechanical objects has been one of the most fascinating research topics in physics. It not only extends the exploration of quantum phenomena to macroscopic scales but also enables ultra-precise measurements of mass, force, displacement, acceleration, and so on.

Our research focuses on the development of ultralow-loss micro- and nano-optomechanical devices and integrated mechanical circuits. These platforms provide unique opportunities for both precision sensing and quantum technologies. By integrating ultralow-loss mechanical systems with superconducting circuits, photonic platforms, or others, we aim to advance interdisciplinary research spanning quantum science, topological physics, biophysics, and spectroscopy.

News
2026.07
Openings
We are recruiting Master and PhD students, postdocs, and RA. See Openings for details.
2026.07
Starting of the group
Dr. Xiang Xi accepted the offer of ZJU Physics, and will join there soon。
Research

What We Work On

⚛️

Ultra-low-loss classical and quantum acoustics

"We develop phononic devices and circuits with state-of-the-art performance. We aim to hybrid those devices with optical, superconducting circuits, and others for sensing and quantum applications. We include the concept of topology into our circuit design."

🔗

Classical and quantum sensing

With one of the best phononic devices we have, we will extend them for various sensing applications. Especially, we focus on the new technique of phononic interferometry.

🌐

Quantum transduction and memory

Based on our the strong coupling of our ultra-low-loss phononic membranes with optical cavity and superconducting circuits, we aim to develop quantum microwave-to-optical transducer and memory for future quantum network.

🎵

New Physics

Our phononic devices are among the best sensors for force, mass, and so on. It is a very good plaform to explore unknown physics. For example, we can use it to explore fundamental formulation of optical force.

Publications

Selected Papers

2025 A soft-clamped topological waveguide for phonons
Xiang Xi†, Ilia Chernobrovkin, Jan Košata, Mads B. Kristensen, Eric C. Langman, Anders S. Sørensen, Oded Zilberberg, Albert Schliesser†
Nature, 642, 947–953
2025 A topological parametric phonon oscillator
Xiang Xi*, Jingwen Ma*, and Xiankai Sun
Advanced Materials, 19, 1056–1061
2023 Membrane-in-the-middle optomechanics with a soft-clamped membrane at milliKelvin temperatures
Eric Planz*, Xiang Xi*, Thibault Capelle*, Eric C. Langman, and Albert Schliesser
Optics Express 31, 41773-41782 (2023)
2022 Highly tunable broadband coherent wavelength conversion with a fiber-based optomechanical system
Xiang Xi, Chang-Ling Zou, Chun-Hua Dong, and Xiankai Sun
Advanced Photonics 4 (5): 056003, Sep. 2022. [featured as cover article].
2021 Experimental investigation of the angular symmetry of optical force in a solid dielectric
Xiang Xi, Jingwen Ma, Zhong-Hao Zhou, Xin-Xin Hu, Yuan Chen, Chang-Ling Zou, Chun-Hua Dong, and Xiankai Sun
Optica 8 (11): 1435-1441, Nov. 2021.
2021 Nanomechanical topological insulators with an auxiliary orbital degree of freedom
Jingwen Ma*, Xiang Xi*, Yuan Li, and Xiankai Sun
Nature Nanotechnology 16 (5): 576-583, May 2021.
2021 Experimental demonstration of dual-band nano-electromechanical valley-Hall topological metamaterials
Jingwen Ma*, Xiang Xi*, and Xiankai Sun
Advanced Materials, 33 (10): 2006521, 2021
2021 Observation of chiral edge states in gapped nanomechanical graphene
Xiang Xi*, Jingwen Ma*, Shuai Wan, Chun-Hua Dong, and Xiankai Sun
Science Advances, 7 (2): eabe1398, Jan. 2021
2021 Graphene-assisted electro-optomechanical integration on a silicon-on-insulator platform
Xiang Xi, Zefeng Chen, Jian-Bin Xu, and Xiankai Sun
Optics Express 28 (10), 14386–14395, 2020.
2020 Carrier-mediated cavity optomechanics in a semiconductor laser
Xiang Xi, Jingwen Ma, and Xiankai Sun
Physical Review A 99 (5): 053837, 2019.

Full list on Google Scholar and ORCID.

People
Principal Investigator
PI
Xiang Xi· 习翔
Tenure-check Assistant Professor, Department of Physics · Zhejiang University
Dr. Xiang Xi received his PhD from the Chinese University of Hong Kong， and subsequently held a postdoctoral position and an assistant professorship at the Niels Bohr Institute, University of Copenhagen. He has been working in the fields of nanomechanics and optics for over ten years.

Dr. Xiang Xi has published more than ten papers in related areas as a (co-)first author or corresponding author in prestigious journals, including Nature, Nature Nanotechnology, Science Advances, and Optica. He has been invited to serve as a reviewer for leading journals such as Nature Physics and Nature Communications, and has delivered invited talks at international conferences, including Phonons 2025. He is the recipient of the Marie Skłodowska-Curie Postdoctoral Fellowship (2023) and the Danish Villum Experiment Grant (2024).
Postdoctoral Researchers
WL
Dr. This can be you · XX
Postdoctoral Researcher
Quantum electromechanics
PhD Students
ZW
This can be you · XX
PhD Candidate (Year x)
Quantum acoustics
Openings

Join the Lab

Postdoctoral Researcher
Open
"We have several postdoc position openning for the research field of ultracoherent phononic circuits, quantum opto- and electromechanics, topological phononics, and so on. The position is fully funded for two years with possibility of extension."
  • PhD in physics, optics, phononics, superconducting circuits, or related field"
  • Experience with opto/electro-mechanical measurements, superconducting circuits, or nanofabrication
  • Good passion on physics and experiments, open for collaboration
PhD Student (2027 intake)
Open
We are accepting PhD applications for the 2027 academic year. Students will have the freedom to choose the research topic that is happening in the lab.
  • Bachelor's or Master's degree in physics or engineering
  • Background in physics, optics, or related
  • Lab experience is a plus
Visiting Students / Interns
Open
We welcome undergraduate, Master's students, exchange student, or others, for short-term research visits (3–6 months). Projects of great fun are available in both theory and experiment.
  • Currently enrolled in a Bachelor's or Master's programme, or gap year student
  • Interest in optics， mechanics，and quantum physics or quantum information