Date: Monday, March 31, 2014 - 3:30pm
"Topology and Quantum Entanglement in Condensed Matter Systems" - Quantum entanglement significantly enriches states of matter at zero temperature. Quantum many-body systems with a finite spectrum gap can be roughly categorized into two different classes: (1) long range entangled states with bulk topological degeneracy (e.g. fractional quantum Hall states); (2) short range entangled (SRE) states with a trivial bulk spectrum (but they can still have protected gapless edge states), such as the integer quantum Hall states, quantum spin Hall states, topological insulators, etc.
Date: Wednesday, April 9, 2014 - 3:30pm
The Memory of Sand: Complex systems are characterized by an abundance of meta-stable states. To describe such systems statistically, one must understand how states are sampled, a difficult task in general when thermal equilibrium does not apply. This problem arises in various fields of science, and here I will focus on a simple example, sand. Sand can flow until one jammed configuration (among the exponentially many possible ones) is reached.