Quantum transport in ultracold atoms

  • Event Date: 2016-06-30
  • AMO/QIS/CMT
  • Speaker: Prof. Chih-Chun Chien (University of California, Merced)  /  Host: Prof. Daw-Wei Wang (NTHU)
    Place: Lecture Room A, 4F, 3rd General Building, Nat'l Tsing Hua Univ.


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.
 
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-ChunChien got his PhD from the University of Chicago in 2009. He moved to Los Alamos National Laboratory, first as a director funded fellow and then was 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.