Quantum Institute: Visitor Schedule

The Quantum Lunch is regularly held on Thursdays in the Theoretical Division Conference Room, TA-3, Building 123, Room 121.
For more information, contact Diego Dalvit.

May 17, 2007
12:30 PM

Rosario Fazio,
International School for Advanced Studies, Italy

Decoherence and Entanglement in Interacting Spin Baths

Abstract

I will discuss decoherence induced on a two-level system coupled to a one-dimensional quantum spin chain. I consider the cases where the dynamics of the chain is determined by the Ising, XY, or Heisenberg exchange Hamiltonian. This model of quantum baths can be experimentally engineered by using atoms in optical lattices. As an example, I show how to implement a pure dephasing model for a qubit system coupled to an interacting spin bath. I will also discuss some results concerning the relation between decoherence and entanglement inside the bath. For the Ising and the XY bath it is possible to obtain an exact expression for the decay of coherences, while for the Heisenberg bath I will present results of numerical simulations using the time-dependent Density Matrix Renormalization Group.