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The world smallest discrete unit of a phenomenon

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.

CTCP Seminar: “Torsional Hall Viscosity of Massive Chern Insulators” by Dr. Weizhen JIA on 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.

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To conduct multi-disciplinary scientific researches on quantum-related subjects and to unleash the full potential of the quantum laws of nature

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consists of internationally leading physicists, computer scientists, mathematicians and engineers, and provides a multi-disciplinary scientific research platform at the University of Hong Kong