学术报告：Quantum transport in cold atoms（冷原子中的量子输运）

报告人：简志钧  博士

报告时间：2017年6月27日10：00，

报告地点：比较靠谱的赌博大平台九龙湖校区田家炳楼南203

Abstract:

Recent advance in cooling and trapping atoms has brought exciting quantum phenomena, including atomic Bose-Einstein condensate (BEC), superfluid, Mott insulator, and topological phases. One realistic yet ambitious goal is to use cold-atoms and optical potentials to simulate and complement electronic devices, and this leads to a thriving field called atomtronics. In contrast to electronic systems, cold-atoms are charge neutral and isolated from their environment. Moreover, strong quantum effects drastically alter transport properties of cold-atoms. I will first review breakthroughs in the study of quantum transport using various cold-atom systems and contrast theoretical descriptions from open- vs. closed- system approaches. Then I will discuss the question of whether quantum memory effects can arise in simple, isolated, and noninteracting systems. Although a lack of competing time scales commonly results in a negative answer, I will show that an affirmative answer can be found in cold-atom systems by utilizing geometrical effects of optical lattices.

摘要：近年来关于原子的冷却与捕获方面的进展实现了很多激动人心的量子现象，如玻色爱因斯坦凝聚、超流、Mott绝缘体和拓扑物相等。该领域的一大颇具野心同时也有实际意义的目标是利用冷原子体系和光势阱来模拟和辅助电子器件。这方面的研究产生了一个新的繁荣的研究方向：原子技术（atomtronics）。与电子系统不同，冷原子体系是电中性的，并和周围环境隔离，同时强量子效应会显著地影响冷原子体系的输运性质。我首先将对冷原子体系输运性质的研究进展以及对应的基于开放或闭合体系的理论描述做一个综述，然后讨论简单、隔离和无相互作用的体系能否实现量子存储效应，并从基于光晶格体系的几何效应的冷原子体系找出积极的结果。

Reference: C. C. Chien, S. Peotta, and M. Di Ventra, “Quantum transport in cold atoms”, Nat. Phys. 11, 998 (2015). C. Y. Lai and C. C. Chien, “Geometry-induced memory effects in isolated quantum systems: Observations and applications”, Phys. Rev. Applied 5, 034001 (2016).

Short bio: Chih-Chun Chien got his BS and MS degrees from National Taiwan University and his PhD from the University of Chicago in 2009. He moved to Los Alamos National Laboratory in USA, first as a director funded fellow and then an Oppenheimer fellow. He is currently a physics assistant professor at University of California, Merced, working on theoretical atomic and molecular physics. He was a recipient of the 2015 Hellman Family Faculty Award. His research covers ultracold atoms, superfluids and superconductors, biomaterials, and mathematical physics, and he has published more than 60 research papers.

报告人简历：简志钧，先后获得台湾大学学士、硕士学位，并于2009年获得芝加哥大学博士学位。他曾在美国洛斯阿拉莫斯国家实验室工作，任奥本海默研究员并获实验室主任基金。他现在是加州大学Merced分校物理系助理教授。他的研究方向为理论原子和分子物理，涵盖了超冷原子、超流、超导、生物材料和数学物理。他已经发表了超过60篇研究论文。