Events

100+ years after its discovery in 1911, superconductivity remains one of the most fascinating and challenging topics in physics. In this talk, the history of superconductor, its physics and applications as well as the recent progress made by Chinese will be reviewed. Several inspiring anecdotes of scientists working in this field will also be highlighted.

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.

Quantum simulation is one of the pillars of Quantum Revolution 2.0. Its essence is to simulate a complicated and hard-to-control quantum system using a simple and controllable one. Ultracold atoms and ions, due to their unprecedented controllability, have become an important platform for quantum simulation. In this talk, I will introduce two recent works in collaboration with my experimental colleagues at Rice. The first work concerns the simulation of electron transfer — an important issue relevant to many biochemical processes and material science — using trapped ions; and the second concerns the simulation of spin-charge separation — a unique phenomenon in one dimensional quantum many-body system — using two-component ultracold Fermi gas. These two works clearly demonstrated the advantages of performing quantum simulation using cold atoms and ions. I will also discuss some future directions based on these works.