Southern University of Science and Technology

Abstract：

Ultracold neutral atoms in optical lattices provide a unique setting for quantum simulation of interacting many-body systems. The high degree of controllability and the capability of detecting quantum entanglement offers an exciting complementary set-up compared with condensed-matter systems. Here, we demonstrate the realization of a Heisenberg antiferromagnet with 70 ultracold bosons. In a spin-1/2 Bose-Hubbard chain, we switch the sign of the spin-exchange interaction and realize an isotropic antiferromagnetic Heisenberg model. Starting from a low-entropy Néel-ordered state, the bosonic antiferromagnet is approached by sweeping a transversal staggered magnetic field. We measure the coherent evolution of the state by probing the quantum correlations and the staggered magnetization. Furthermore, the characteristic spin-rotational symmetry of the state and its robustness against decoherence is verified. This achievement represents a starting point for exploring a novel form of quantum magnetism in the cold-atom simulator.

References:
[1] Realization of a Bosonic Antiferromagnet. Nat. Phys. 17, 990-994 (2021). 
[2] Cooling and Entangling Ultracold Atoms in Optical Lattices. Science 369, 550-553 (2020).

About the speaker: 
Dr. Bing Yang is an associate professor in SUSTech. He received the B. S. from the Harbin Institute of Technology (HIT) and his PhD from the University of Science and Technology of China (USTC). Dr Yang spends most of his PhD and his first postdoctoral career in Heidelberg (2012-2019). Then, he joined the University of Innsbruck as a senior postdoctoral fellow until 2021. His research interests focus on studying quantum many-body physics with ultracold quantum gases, aiming to simulate or solve complex problems in condensed matter physics and high-energy physics.

Inviter：胡海平（82649070）