Physics & Astronomy Colloquium

3:30 PM, Friday, February 16, 2007
Room 155, Chem-Phys Building

Dr. Karyn Le Hur
Department of Physics
Yale University

"Quantum entropy between a spin and its environment''

The concept of quantum entropy appears in multiple contexts, from black hole physics to quantum information theory, where it measures the entanglement of quantum states. Prompted by the link between entanglement and quantum criticality, a number of researchers have begun to study the entanglement entropy of condensed matter systems. We employ the spin-boson model to describe the entanglement entropy between a spin and its environment. We obtain exact analytical results which are complemented by the Numerical Renormalization Group approach. Connections between quantum entropy, decoherence, Kondo physics and quantum criticality is discussed. We also emphasize the possibility of measuring this quantum entropy using mesoscopic devices and cold atomic boson systems.

Refreshments will be served in CP 179 at 3:15 PM