报告题目 (Title)：Pattern Formation and Exotic Order in Driven-Dissipative Bose-Hubbard Systems（在驱动-耗散的玻色-哈伯德系统中的图案结构产生和新奇序）

报告人 (Speaker)：蔡子 研究员（上海交通大学）

报告时间 (Time)：2021年10月19日(周二) 10:30-12:00

报告地点 (Place)：校本部 G309

邀请人 (Inviter)：张永平

摘要 (Abstract)：

Modern experimental platforms such as superconducting circuit arrays call for the exploration of bosonic tight-binding models in unconventional situations with no counterpart in real materials. Here we investigate one such situation in which excitations are driven and damped by pairs, leading to pattern formation and exotic bosonic states emerging from a nonequilibrium quantum many-body system. Focusing on a two-dimensional driven-dissipative Bose-Hubbard model, we find that its steady states are characterized by the condensation of bosons around momenta lying on a “Bose surface”, a bosonic analog of the Fermi surface in solid-state systems. The interplay between instabilities generated by the driving, the nonlinear dissipative mode coupling, and the underlying lattice effect allows the system to equilibrate into an exotic superfluid state of bosons condensed on a closed ring in momentum space instead of discrete points. Such an unconventional state with a spatially uniform density distribution goes beyond the traditional scope of pattern formation and thus has no counterpart in the classical literature.

报告人简介：

蔡子，上海交通大学特别研究员。 2010年中科院物理所获得博士学位。先后在美国加州大学圣迭戈分校，德国慕尼黑大学，奥地利科学院量子光学与量子信息研究所从事博士后研究。主要研究方向为量子多体物理中的理论和数值计算。研究领域包括凝聚态物理，冷原子系统，以及量子开放系统中涌现的强关联物理。