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Prof. Sir Anthony James Leggett, Nobel Laureate and Advisory Committee Chair, Passes Away at 87 It is with deep sorrow that we announce the passing of Professor Sir Anthony James Leggett on March 8, 2026, at the age of 87. As the chair of the advisory committee of the Hong Kong Institute of Quantum Science & Technology (HKIQST) and a distinguished 2003 Nobel Laureate in Physics, his contributions have left an indelible mark on the scientific community. Beyond his work on superfluid Helium-3, for which he was awarded the 2003 Nobel Prize, he pioneered the study of the quantum mechanics of collective variables, and, importantly, the phenomena of quantum coherence and tunnelling in the presence of a dissipative environment. This led not only to a substantial body of technical work, but also to a deeper understanding of quantum mechanics as applied to macroscopic systems. Since 2014, he has served as an advisor to the Center of Theoretical and Computational Physics at the University of Hong Kong. Most recently, as chair of the advisory committee for HKIQST, he provided invaluable advice, contributed to the selection of Dan Tsui Fellows, and delivered a series of ten lectures on superconductivity in 2024. We extend our heartfelt condolences to his family and friends. Professor Leggett’s legacy will continue to inspire future generations of scientists. He will be dearly missed.
After a general introduction to the cavity control of quantum materials across condensed matter systems, chemical reactions, and superconducting quantum circuits, I will discuss recent advances in our understanding of collective quantum dynamics, critical behavior, and emergent functionalities in multimode cavity QED systems in the non-perturbative regime.
This lecture series provides a systematic introduction to the Algebraic Bethe Ansatz (ABA), also known as the Quantum Inverse Scattering Method (QISM): a powerful framework for solving quantum integrable models exactly. We will begin with its basic construction, demonstrating how to obtain the exact spectra of paradigmatic models such as the Heisenberg spin chain, the Lieb-Liniger model, and the 6-vertex model. We will then explore the rich mathematical structure underlying the method, focusing on the central role of the Yang-Baxter equation and its profound connection to quantum group theory. If time permits, we will discuss extensions of the formalism to compute dynamical quantities, such as form factors and correlation functions, illustrating the full power of ABA as a tool for non-perturbative analysis in quantum theory.