What’s New

We are thrilled about the appointment of Professor Yi Yang as the Belinda Hung Outstanding Young Professor. Outstanding Young Professorships were featured for the first time at the Thirteenth Inauguration of Endowed Professorships held by The University of Hong Kong (HKU) on 25 November 2024, celebrating six new Endowed Professorships and two new Outstanding Young Professorships. Professor Yi Yang, the HKIQST fellow was gifted the Belinda Hung Outstanding Young Professorship. Professor Yang’s contributions have been recognized with numerous prestigious awards, including the 2024 Xplorer Prize and the 2024 Croucher Tak Wah Mak Innovation Award for Pioneering Photonics Research. His accolades also include being named a Physical Science Fellow in the 2023 Asian Young Scientist Fellowship, being recognized as one of the Innovators under 35 (China) by MIT Technology Review in 2022 and receiving the 2022 Excellent Young Scientists Fund (Hong Kong and Macau) from the National Natural Science Foundation of China, an organization managed by the Ministry of Science and Technology (MOST). Please click here for the list of Professorships.

During this colloquium, the unnoticed beauty of multiband of iron-based superconductors will be highlighted, including i) emerge of topological band which coexists with superconductivity, leading to the discovery of Majorana zero mode; ii) Interplay of multicomponent superconductivity, leading to the discovery of exotic paring with time-reversal symmetry breaking and fractional vortex; iii) Contribution of Hund coupling towards pairing in this unique class of superconductors.

The Kitaev model is an exactly solvable quantum-spin-liquid model defined on a honeycomb lattice with S = 1/2. The key element underlying this model is the bond-anisotropic Kitaev interaction. However, in a spin-only system, it is unrealistic to have such anisotropic interactions. In this talk, I will show that the Kitaev interaction can be realized in a Mott insulator α-RuCl3, which has an effective spin of 1/2 by entangling the spin and orbital degrees of freedom. I will also show that by applying an in-plane magnetic field, the zigzag magnetic order ground state in α-RuCl3 can be completely suppressed, and a quantum-spin-liquid state can be induced. More recently, we extend the Kitaev physics to higher-spin system, where we find in a honeycomb-lattice antiferromagnet Na3Ni2BiO6 that there is a profound 1/3 magnetization plateau, which is stabilized by the Kitaev interaction, as evidenced from the neutron spectroscopy. This will also be discussed in the presentation.