Research

Non-Hermitian topological quantum physics

Non-Hermitian systems with open boundaries are ubiquitous in the quantum world. While the interactions with external environment are widely considered as the main source of loss and decoherence in a quantum system, strategically arranged non-Hermiticity with engineered symmetries and topologies provides new paradigms for quantum information processing. We experimentally explore the physics of non-Hermitian topology on hybrid quantum platforms and leverage the insights for robust generation and manipulation of quantum states.

Related work:

H. Zhao, P. Miao, M. H. Teimourpour, S. Malzard, R. El-Ganainy, H. Schomerus, L. Feng. Topological hybrid silicon microlasers. Nat. Commun. 9, 981 (2018).

H. Zhao, X. Qiao, T. Wu, B. Midya, S. Longhi, L. Feng. Non-Hermitian topological light steering. Science 365, 1163-1166 (2019).

Quantum frequency conversion

Interconversion between microwave and optical photons at the single-photon level is the key technology for superconducting qubit-based distributed quantum information processing. We develop integrated electro-optomechanical quantum transducers that provide optical interfaces to superconducting quantum circuits and engineer optical quantum links across different quantum hardware platforms.

Related work:

H. Zhao, W. D. Chen, A. Kejriwal, M. Mirhosseini. Quantum-enabled microwave-to-optical transduction via silicon nanomechanics. Nat. Nanotech. 1-7 (2025).

H. Zhao. Building photonic links for microwave quantum processors. Nanophotonics (2025).

Acousto-optic information processing

Optomechanical interaction at the nanoscale provides a versatile toolbox for the control of light on heterogeneously integrated photonic platforms. We create new approaches to engineer scalable integrated acousto-optic devices and leverage their low footprint and high efficiency for disruptive optical computing archetectures in both classical and quantum regimes. 

Related work:

H. Zhao, B. Li, H. Li, M. Li. Enabling scalable optical computing in synthetic frequency dimension using integrated cavity acousto-optics. Nat. Commun. 13, 5426 (2022).

H. Zhao, A. Bozkurt, M. Mirhosseini. Electro-optic transduction in silicon via gigahertz-frequency nanomechanics. Optica 10, 790-796 (2023).