HK Forum on Quantumology 香港量子學論壇| Sunday, 23 November 2025 | RHT HKU
We are pleased to announce the HK Forum on Quantumology香港量子學論壇 , held in celebration of the International Year of Quantum Science and Technology (IYQ). The event is organized by the HK Institute of Quantum Science and Technology in collaboration with the HK Branch of the Quantum Science Centre of the Guangdong-Hong Kong-Macau Greater Bay Area.
Scheduled for 23 November 2025 at the Rysan Huang Theatre, of HKU, this event offers a distinguished platform for academic exchange, collaboration, and innovation in quantum science and technology.
You are cordially invited to participate in a series of engaging activities, including keynote and invited talks, as well as roundtable discussions featuring leading quantum scientists. The event program includes:
Please find tentative program:
09:00 – 09:20: Welcome Address
09:20 – 09:30: Inauguration Ceremony (HK Branch for QSC)
09:30 – 12:20: Key-note Presentations
14:00 – 16:30: Invited Talks
16:50 – 17:50: Round Table Discussion
(An interactive forum for knowledge exchange and collaboration)
Please register at no cost using the link below to secure your participation and receive additional event details. Kindly note that, due to the HKU visitor registration system, you will need to bring and present the confirmation email upon entry.
We look forward to your valuable contribution to this landmark celebration of quantum science and technology.
[Registration]
For HKU members (HKU Portal login is required):
https://hkuems1.hku.hk/hkuems/ec_hdetail.aspx?ueid=103117
For non-HKU members:
https://hkuems1.hku.hk/hkuems/ec_hdetail.aspx?guest=Y&ueid=103117
CTCP SEMINAR: “Torsional Hall Viscosity of Massive Chern Insulators” by Dr. Weizhen JIA | Wednesday, November 26, 2025, 4:00pm Room 522, 5/F, Chong Yuet Ming Physics Building, HKU
In this talk I will discuss a non-dissipative, parity-odd transport of (2+1)-dimensional relativistic fermions generated by torsion, namely the torsional Hall viscosity. After introducing the torsional Hall viscosity of massive Dirac fermions, I will discuss two experimentally relevant deformations of this phenomenon. Firstly, in the presence of a constant electromagnetic field, we find that the magnetic field induces a contribution to the torsional Hall viscosity that competes with the one originating from the Dirac mass. Then, we consider the band structure deformation quadratic in momentum terms that was proposed by Bernevig–Hughes–Zhang (BHZ). We find that the BHZ deformation enhances the torsional Hall viscosity in magnitude, but reverses its sign as compared to the standard massive Dirac fermion, indicating a Hall response in opposite direction to the typical Hall viscous force. Nevertheless, the torsional Hall viscosity still discriminates between topologically trivial and nontrivial regimes. These results pave the way for a deeper understanding of the topological response due to torsion and its possible verification in experiments.
“Complex shaping of light: metamaterial design and topology” by Dr. Haiwen WANG | Wednesday, November 12, 2025, 3:00pm Room 522, 5/F, Chong Yuet Ming Physics Building, HKU
Shaping and controlling electromagnetic waves have wide-ranging scientific and practical implications. In this talk, I will present a few theoretical proposals to generate novel topological structures in light. In particular, I show that the transmission nodal lines are general topological responses from non-local metasurfaces and can be used to generate spatiotemporal optical vortices. Additionally, I discuss the possible topological structures that can occur in electromagnetic waves. I show that three-dimensional topological structures, known as hopfions and Shankar skyrmions can be created in free-space electromagnetic waves. Such complex shaping of light may be used for optical emulation of new topological physics, or be used in optical trapping and manipulation applications.
“High-Tc superconductivity based on low-dimensional materials platforms” by Prof. Zhenyu ZHANG | Thursday, November 6, 2025, 4:30pm Room 522, 5/F, Chong Yuet Ming Physics Building, HKU
Discoveries of new superconductors with high transition temperatures have been a perpetual drive of condensed matter physics. In this talk, I attempt to give an overview on recent advances in this vibrant area, with some of own stories squeezed in. We start from predictive designs of freestanding or supported superconducting monolayers that may exhibit high-Tc superconductivity, as well as low-dimensional systems that display exotic Ising, chiral, or p-wave superconductivity. On the mechanistic side, I will demonstrate how plasmonic excitations or pronounced correlation effects can enhance the superconductivity of iron-based superconductors, and predict designer substrates that may optimize the strain in La3Ni2O7 thin films for maximally enhanced Tc.
“Epitaxial Large-gap topological insulator on semiconductor for seamless device integration” by Prof. Feng LIU | Thursday, November 6, 2025, 3:30pm Room 522, 5/F, Chong Yuet Ming Physics Building, HKU
Significant advances have been made in fundamental research of topological insulators (TIs), yet their device applications remain elusive. We propose an approach towards seamless integration of two-dimensional (2D) TIs into semiconductor devices. Using first-principles calculations, we show that heteroepitaxially grown III-V semiconductor ultrathin films can self-convert into 2D TIs. Remarkably, on GaSb(111) monolayer GaAs1-xBix becomes universally a 2D TI at any alloy concentration, x, enabled by natural formation of semiconductor heterojunctions. For the GaAs-rich monolayer, having type-II (III) band alignment with GaSb, an intriguing interfacial band offset inversion emerges between surface Ga-s and substrate Sb-p bands; for the GaBi-rich monolayer, with type-I (I’) alignment, the conventional intra-surface band gap inversion arises between Ga-s and Bi-p bands. The lattice-matching epitaxy of GaAs0.25Bi0.75 alloy enables growth of thin-film 2D TIs with a gap up to ~330 meV. Our findings pave the way to engineering wafer-scale large-gap 2D TIs to potentially operate at room temperature.
Physics Colloquium: “Cold-atom quantum sensing via Bayesian quantum estimation” by Prof. Chaohong LEE | Wednesday, October 22, 2025, 10:30a.m. MWT2, G/F, Meng Wah Complex, Main Campus, HKU
Quantum sensors based on frequentist interferometry face a trade off between
sensitivity and dynamic range Bayesian quantum estimation, combining Bayesian
statistics with quantum metrology, can surpass the limit of conventional frequentist
measurements For cold atom CPT clocks, our adaptive Bayesian protocol achieves
Heisenberg limited sensitivity in integration time and improves fractional frequency
stability by 5 1 4 dB over conventional PID locking while enhancing robustness against
technical noise In CPT magnetometry, we optimize measurement sequences to
improve precision scaling from T 0 5 to T 0 85 Using Bayesian quantum estimation to
optimize the interferometry sequence, we yield a 145 6 nT dynamic range 14 6 dB
higher than frequentist counterpart of 5 0 nT) with a sensitivity of 6 8 0 1 pT/Hz¹ ² 3 3
dB improvement over the frequentist counterpart of 14 7 0 4 pT/Hz¹ ²) In addition to
atomic clocks and magnetometers, this framework may bridge high sensitivity and
broad dynamic range for other interferometry based quantum sensors.
HKIQST and Sun Yat-sen University IAS SYU Signed Strategic MOU to Advance Quantum Research
The HK Institute of Quantum Science & Technology (HKIQST) 香港大学香港量子研究院at The University of Hong Kong (HKU) and the Institute for Advanced Study (IAS) of Sun Yat-sen University (SYU) 中山大学高等研究院 have officially signed a Memorandum of Understanding (MOU) to deepen collaboration in quantum science and technology across the Greater Bay Area.
The MOU, signed on October 11, 2025, by Professor Zidan Wang (汪子丹) on behalf of HKU IQST and Professor Daoxin Yao (姚道新) representing Sun Yat-sen University IAS, marks a significant step toward building a strategic partnership between two leading academic institutions in the region.
Under the agreement, both parties will:
· Serve as a bridge for collaborative research between HKU and Sun Yat-sen University in advanced quantum technologies and related fields.
· Jointly participate in academic activities across the Greater Bay Area, including establishing shared research platforms and applying for strategic funding opportunities.
· Promote the exchange of researchers, including professors, visiting scholars, and graduate students, and co-host academic events such as forums, workshops, and summer schools.
The MOU also outlines mutual commitments to confidentiality, dispute resolution, and responsible use of institutional branding, ensuring a respectful and productive partnership.
This collaboration reflects a shared vision to accelerate innovation, foster academic exchange, and contribute to the development of quantum science in the region.
🔗 Learn more about HKU IQST: https://iq.hku.hk
🔗 Visit Sun Yat-sen University IAS: https://iash.sysu.edu.cn
Prof. Qi Zhao featured in Nature Physics and awarded major national grant
The Hong Kong Institute of Quantum Science & Technology (HKIQST) is proud to celebrate the outstanding accomplishments of our fellow, Professor Qi Zhao.
🧠 National Recognition in Quantum Research
Professor Zhao has been awarded the MOST National Science and Technology Major Project 2024 (科學技術部_国家科技重大专项2024) as Principal Investigator in the field of Quantum Communication and Quantum Computers (量子通信与量子计算机). This prestigious Young Scientist Project (青年科学家项目) has secured a total funding of 5 million CNY, marking a significant milestone in advancing quantum technologies.
📘 Cover Feature in Nature Physics
Professor Zhao’s recent research has been published in Nature Physics and selected as the cover article for Volume 21, Issue 8. This work highlights cutting-edge developments in quantum science and reflects the global impact of HKIQST’s research community.
We extend our warmest congratulations to Professor Zhao for these remarkable achievements and look forward to his continued contributions to the quantum frontier.
CTCP Seminar: “A 2D-CFT Factory: Critical Lattice Models from Competing Anyon Condensation in SymTO” by Prof. Yidun WAN | Thursday, September 25, 2025, 4:30pm CYMP522
There is a holographic correspondence between (1) nD quantum systems with symmetry C and (2) nD boundaries of the n+1D topological order Z(C), where Z(C) is mathematically the Drinfeld center of C. Such mysterious topological holography has numerous applications and consequences, especially in the recent emerging field of generalized symmetry. By a rigorous construction and proof in 1+1D, we show that the Drinfeld center Z(C) naturally arise as the category of fixed-point local tensors with symmetry C, thus revealing the origin of topological holography. This talk is based on arXiv:2412.07198.
Joint Seminar: “Beyond Closed Wave Systems: Non-Hermiticity, Nonlinearity, and Casimir Effect” by Prof. Kun DING | Wednesday, August 20, 2025, 11:00am CYMP522
The classical wave system has demonstrated itself as an excellent platform to realize and
investigate novel phenomena and physics. The bedrock principle is to utilize the macroscopic
quantities obtained from the homogenization or mean-field treatment. However, it usually deals
with Hermitian problems and averages out fluctuations. Therefore, the presentation will cover two
topics: non-Hermitian physics and Casimir effect. The first part focuses on the impact of non
Hermitian ingredients on soliton formation and dynamics. By constructing a soliton phase diagram,
two distinct soliton phases and their transitions are identified. A Wannier-function-based nonlinear
Hamiltonian shows that soliton formation critically depends on how skin-mode localization and
band nonreciprocity suppress or enhance wave dispersion. Both soliton phases have been
demonstrated to be dynamically accessible from bulk and edge excitations. The second part
discusses the influence of the metal’s surface electrons on Casimir forces. A three-dimensional
frame transformation method has been established by embedding mesoscopic boundary conditions
of electromagnetic fields. We find that mesoscopic Casimir forces are sensitive to the surface
electron behavior, including spill-in and spill-out, as verified by the multiple scattering method and
proximity force approximation. The mechanism has finally been revealed as Casimir softening
distances rooted in quantum surface responses of electrons.
