2012

= Fall 2012 =

//Orbital Physics in one dimension//
 * Sep 3rd, Xiaopeng Li,**

Spinor BEC with spin-orbital couplings
 * Sep 10th,** **Zhifang Xu,**

Anisotropic Topological Superfluid Phase of a 3D Dipolar Fermi Gas
 * Sep 17th, Bo Liu**,

Quantum Dynamics of quenched lattice systems
 * Sep 24th,** **Jin-Long Yu**

Superconductivity with repulsion in one dimension
 * Oct 10th, Xiaopeng Li**

Low energy excitations of Bose gases with spin-orbit coupling
 * Oct 31st (Wed 5pm Santa Barbara time), Zhifang Xu**

Itinerant Ferromagnetism in Spin-Orbit Coupled Fermi Gases
 * Nov 15 (Thursay 9:30 am Beijing Time), Bo Liu,**

Interaction effects in Kitaev's 1D chain
 * Nov 20 (Tuesday 9:30 am Beijing Time), Jin-Long Yu,**

low dimensional spin imbalanced Fermi gases in strong coupling limit
 * Dec 4, W. Vincent Liu, (in the super joint group meeting)**

Quench Dynamics as a probe of ``hidden" angular momentum ordering
 * Dec 11, Xiaopeng Li**

= Summer 2012 =

//Reference:// http://arxiv.org/abs/1205.0254 Abstract: We unveil a topological phase of interacting fermions on a two-leg ladder of unequal parity orbitals, derived from the experimentally realized double-well lattices by dimension reduction. $Z_2$ topological invariant originates simply from the staggered phases of $sp$-orbital quantum tunneling, requiring none of the previously known mechanisms such as spin-orbit coupling or artificial gauge field. Another unique feature is that upon crossing over to two dimensions with coupled ladders, the edge modes from each ladder form a parity-protected flat band at zero energy, opening the route to strongly correlated states controlled by interactions. Experimental signatures are found in density correlations and phase transitions to trivial band and Mott insulators.
 * May 9th,** **Xiaopeng Li,** //Topological orbital ladders//

//Reference:// [|arXiv:1205.1521] I'll discuss our recent preprint. //Abstract: // We discuss a scheme to measure the many-body entanglement growth during quench dynamics with bosonic atoms in optical lattices. By making use of a 1D or 2D setup in which two copies of the same state are prepared, we show how arbitrary order Renyi entropies can be extracted using tunnel-coupling between the copies and measurement of the parity of on-site occupation numbers, as has been performed in recent experiments. We illustrate these ideas for a Superfluid-Mott insulator quench in the Bose-Hubbard model, and also for hard-core bosons, and show that the scheme is robust against imperfections in the measurements.
 * May 16th, Johannes Schachenmayer,** //Measuring entanglement growth in quench dynamics of bosons in a optical lattice//

Reference: (1) X. Li's unpublished notes and (2) [|PRB 61, 2497 (2000) by U. Ledermann and K. Le Hur]
 * July 6th, Xiaopeng Li**, Exotic superconducting phases on the sp-orbital ladder

Reference: To be posted
 * July 10th, Andrew Daley**, Steady-state spin squeezing in hot reactive fermions

= Spring 2012 =
 * Tuesday 12:30PM-2:30PM, 316 Allen Hall **


 * Jan 10, Johannes Schachenmayer **, //Dynamical Crystal Creation With Polar Molecules or Rydberg Atoms in Optical Lattices//

Reference: J. Schachenmayer, I. Lesanovsky, A. Micheli, and A. J. Daley, “Dynamical crystal creation with polar molecules or Rydberg atoms in optical lattices,” New Journal of Physics, vol. 12, no. 10, p. 103044, Oct. 2010. http://iopscience.iop.org/1367-2630/12/10/103044/


 * Jan 17, ** **Saubhik Sarkar**, //Quantum simulation of antiferromagnetic spin chains in an optical lattice//

Reference: Nature 472, 307

Reference: arXiv:1201.3253
 * Jan 24, ** **Bin Wang**, //Probing Atomic Majorana Fermions in Optical Lattices//


 * CMT Faculty Candidate Lunch Talks**
 * 12:00PM - 1:00PM, 318 Allen**


 * Jan 27, Friday, Wayne Witzel**, //Informal lunch discussion on "Simulating a Solid State Spin Qubit in a Spin Bath"//


 * Jan 31, Tuesday, Kai Sun**, //Informal lunch discussion on "Topological Insulators, Topological Semimetals, and Quantum Hall effects without Landau Levels"//


 * Feb 3, Friday, Doron Bergman**, //Informal lunch discussion on "The Topological Insulator in a Fermi Sea—Sink or Swim"//


 * Feb 7, Tuesday, Suk Bum Chung**, //Informal lunch discussion on "Detecting Majorana Fermions in Topological Superconductors"//


 * Feb 10, Friday, Alexey Gorshkov**, //Informal lunch discussion on "Many-body Physics with Atomic, Molecular, and Optical Systems and Methods"//


 * Feb 14, Tuesday,** **Ying-Dan Wang**, //Informal lunch discussion on "Fighting against Thermal Noise in Quantum Opto- and Electro-mechanical Systems"//


 * Feb 17, Friday,** **Liang Jiang**, //Informal lunch discussion on "Quantum Information Processing with Spins and Topological Quantum Systems"//


 * Resume Group Meeting**
 * Tuesday 12:30PM-2:30PM, 316 Allen Hall **


 * Feb 21,** **March Meeting Rehearsal**
 * Li, Xiaopeng,** //Time reversal symmetry breaking of p-orbital bosons in a one-dimensional optical lattice//
 * Schachenmayer, Johannes**, //Cold bosons in noisy optical lattices//
 * Stefanus**, //Search for conformal invariance in 2-D compressible turbulence//
 * Wang, Bin**, //Quantum Dynamics of Population-Imbalanced Fermi Mixture in One-dimensional Optical Lattices//


 * Feb 28,** //No group meeting (APS March Meeting)//


 * Mar 6, Tuesday 12:30 316 Allen (Group Meeting), Adrian Kantian (University of Geneva)**, //Mobile impurities in 1D cold gases//


 * Mar 7, Wednesday 12:00 318 Allen (Pizza Lunch), Ulf Bissbort (University of Frankfurt)**, //Quasi-particle theory and dynamics of strongly interacting bosons in optical lattices//

> **Prof. W. Vincent Liu**, //Background gauge field approach to topological invariants in superconductivity//
 * Mar 13, Xiaopeng Li,** //A topological insulator without artificial gauge fields//


 * Mar 20, Prof. David Weiss (Penn State University)**, //Informal discussion on "Experiments with Atoms in Optical Lattices"//

Reference: Nature Physics 6, 806–810 (http://www.nature.com/nphys/journal/v6/n10/abs/nphys1754.html) Reference: Keldysh Formalism Reference: Giamarchi lecture notes
 * Mar 27, ** **Johannes Schachenmayer**, //Pink noisy lattices and the analytical Luttinger liquid methods from//

Reference: arXiv:1202.2649 Reference: //Cavity quantum electrodynamics for superconducting electrical circuits: An architecture for quantum computation//, Phys. Rev. A 69, 062320 (2004)
 * Apr 3, Bin Wang**, //Resonantly Tunable Majorana Polariton in a Microwave Cavity//


 * Apr 10,** //No group meeting//

Abstract: Cold atomic gases in optical lattices offer the possibility to study strongly correlated condensed matter systems and provide tools in the implementation of quantum information processing. A key challenge in experiments is that they require very low temperatures. We study different heating mechanisms in these setups and in this talk I present our results on heating arising due to classical (stochastic) fluctuations of the depth of the lattice potential. Further I present a lattice setup that allows minimizing or even canceling the heating effects of such fluctuations. If I have time in the end, I will briefly talk about an other project where we try to find schemes to measure entanglement (linear entropy) in many-body systems of cold atoms in optical lattices.
 * Apr 17, Hannes Pichler (University of Innsbruck),** //Many-body dynamics of cold atoms in noisy optical lattices//

Reference: [] Theory part: //Propagation front of correlations in an interacting Bose gas// Reference: []
 * Apr 24,** **Saubhik Sarkar,** //Light-cone-like spreading of correlations in a quantum many-body system//