Prof. Gyu-Boong Jo is currently Hari Harilela Associate Professor in the Department of Physics at The Hong Kong University of Science and Technology (HKUST), and leads the Laboratory for Ultracold Quantum Gases. He joined HKUST following his studies at the Massachusetts Institute of Technology (PhD, 2010), where he was awarded the Samsung PhD Fellowship, and postdoctoral work at the University of California, Berkeley (2010-13). He obtained his Bachelor’s degrees in physics and mathematics from Seoul National University in 2003. He has received multiple awards including the AKPA Outstanding Young Researcher Award (OYRA) (2013), the Early Career Award from the Research Grant Council of Hong Kong (2014), the Croucher Innovation Award (2016), the HKUST School of Science Research Award (2019) and the RGC Research Fellowship (2021).
Prof. Gyu-Boong Jo’s research focuses on the quantum simulation of intractable quantum problems using ultracold atoms, wherein a dilute gas of atoms is routinely cooled down to 100 billionth of 1 Kelvin. He harnesses the long quantum coherence of atoms to engineer atomic systems, and creates synthetic quantum matter for simulating various many-body quantum dynamics, including topological phases, many-body open quantum states, large spin quantum states and dipolar quantum liquids. To do so, he utilizes atomic quantum simulators and explores the interface between atomic molecular optical physics, condensed-matter physics and quantum information science. His research agenda continues to evolve and aims at developing a programmable quantum simulation platform for quantum computation.
Given that various synthetic topological matter have been realized with ultracold atoms, the atomic system has become one of most promising platforms for examining topological phases of matter in unprecedented environments, such as those with dissipation. Although such environments are ubiquitous in nature, it is still challenging to exploit them to manipulate the property of the quantum system in which emergent phenomena, such as exceptional points/rings, skin effects, localization, and critical phases, occur. In this talk, I discuss our recent realization of dissipative spin-orbit couplings (SOCs) in bulk and lattices with ultracold fermions.
In bulk, we realize non-Hermitian spin-orbit-coupled quantum gases and observe a parity-time symmetry- breaking transition across the exceptional point (EP) as a result of the competition between SOC and dissipation. The realized EP of the non-Hermitian band structure exhibits chiral response when the quantum state changes near the EP. Recently, we generalize this non-Hermitian SOC scheme to two-dimensional Bloch bands, in which the EP emerges at the end of Fermi arc in the presence of dissipation. By using spin-resolved Rabi spectroscopy in this lattice system, we not only identify the exceptional point but also measure a complex energy-gap spectrum showing the evidence of non-Hermitian skin effect in a two-dimensional lattice system.