<注：本视频仅用于学术交流，版权归报告人所有>

►【“凝聚态物理-中关村论坛”第400次讲座】

题目：Emergent space-time from a quantum phase transition

时间：2022年8月29日（星期一）下午2点

报告人：叶锦武 教授，Mississippi State university/Westlake university

地点：线上/中科院物理所M楼830会议室

报告摘要：

P.W. Anderson said " More is different ". It says the macroscopic quantum phenomena such as superfluids, superconductors, quantum anti-ferromagnetism, fractional quantum Hall states, etc emerge as the number of interacting particles gets more and more. However, he left the question how these emergent quantum or topological phenomena change under different inertial frames. In this talk, we try to address this outstanding problem. We propose there is an emergent space-time corresponding to any emergent quantum phenomenon, especially near a quantum/topological phase transition (QPT).  We explore the emergent space-time in one of the simplest QPTs:  Superfluid (SF)-Mott transitions of interacting bosons in a square lattice. By both constructing effective actions and performing microscopic calculations on a lattice, we show that a Mott phase near the QPT may tune into a SF phase, but not the other way around.  We also demonstrate many other novel effects of observing emergent quantum phenomena in a different inertial frame.  Contrast to the Doppler shifts in a relativistic quantum field theory and Unruh effects in an accelerating observer are made.  Doing various light or neutron scattering measurements in a moving sample may become an effective way not only measure various intrinsic properties of the materials, tune various quantum and topological phases through novel phase transitions, but also probe the new emergent space-time structure near any QPT.

报告人简介：

Prof. Ye received his Ph.D. from Yale University. Now he is a Professor at Mississippi state university. He has been a long term visitor at the Institute for Theoretical Sciences, Westlake University since last Fall. Prof. Ye's research covers wide areas of theoretical physics such as condensed matter theory quantum optics, cold atom physics and non-relativistic quantum field theory. Recently, he mainly focuses on the emergent quantum and topological phenomena of interacting electrons, spins and photons, also extends to conformal field theory, gravity and quantum black holes from materials point of views.