Choi, Jae-yoon

Dynamic scaling of far from equilibrium dynamics in quantum many-body systems

Jae-yoon Choi - Korea Advanced Institute of Science & Technology (KAIST), Daejeon, Korea

Abstract: Understanding and classifying out-of-equilibrium dynamics in a closed quantum many-body system have been outstanding problems in modern physics. In this talk, I will introduce our recent experimental results on the universal dynamics far from equilibrium. In the first talk, a spin-1 Bose-Einstein condensate is adopted to study universal coarsening dynamics, where we quench a polar phase to ferromagnetic phases by microwave dressing. Right after the quench, we observe the emission of spin 1/-1 pairs due to dynamical instability, forming microdomains, which are coarse to form a larger domain as time evolves. We find distinctive scaling behavior depends on the symmetry of the Hamiltonian and associated dynamics of topological defects. In the second part, I will present the observation of Family-Visek scaling in 1D XX Heisenberg chains, where we implement quantum gas microscopy for single atom detection and manipulate initial states. Investigating post-quench dynamics of a charge density wave state at different chain lengths L=8-16, we measure ballistic dynamical scaling exponent. Moreover, we observe the ballistic transport is changed to diffusive under random kick during the dynamics.