Morning Talk: Making Contact for p-wave Resonance: Theory and Experiment

10:30-12:00, 高研院三楼322报告厅

Shizhong Zhang ( Department of Physics, Hong Kong University )

Abstract: I discuss some universal properties associated with p-wave resonance and derive a set of exact relations analogous to the s-wave resonance. However, in contrary to the s-wave case, the effective range R is crucial for a consistent theoretical formulation. As a result, one obtains two set of adiabatic relations, one associated with scattering volume v and the other R. Experimental evidences for the existence of these two contacts via radio-frequency spectroscopy is presented and a measurement of energetics close to p-wave resonance is accomplished using the adiabatic theorems. Dynamical growth of contacts is monitored and is related to the population of closed channel p-wave dimers. I conclude by discussing some remaining theoretical problems that are still worth investigating.

Afternoon Talk: Surprises in the Simulation of Quantum Phase Transitions

2:30-4:00, 高研院三楼322报告厅

Lei Wang ( Institute for Theoretical Physics, ETH Zürich )

Abstract: I will talk about two recent surprises in the simulation of quantum phase transitions.

Surprise one is the solution of a thirty years old sign problem by the continuous-time QMC approach and the Majorana fermion representation. Practically, it enables us to study several unconventional quantum critical points unbiasedly to high precision. Conceptually, the attempts to unify the two solutions deepen our understanding of the sign problem and provide a new guideline for sign-problem-free QMC simulation of correlated fermions.

Surprise two is a generic, efficient and elegant approach to compute fidelity susceptibility of correlated fermions, bosons, and quantum spin systems in modern QMC methods. It can be used to detect quantum phase transitions without any prior knowledge of the local order parameter. Using it I will shed light on the hypothetical spin-liquid phase in the Hubbard model on honeycomb lattice.

I will address the relevance of these developments to ultracold atom experiments throughout the talk.

Afternoon Discussion: Free Discussion on Recent Developments in Cold Atoms

4:30-6:00, 高研后花园