Colloquium 2008-03-06

 

3:30 p.m. in Room 307 of the Optical Sciences Meinel Building

Speaker:

Poul Jessen

University of Arizona College of Optical Sciences

Title:

Quantum Control of Atomic Spins

Host:

Stanley Pau

 

Abstract: Laboratory techniques to manipulate and observe ultracold atoms make these a superb platform on which to develop and test new ideas in quantum control and measurement. I will discuss a series of recent experiments in which we use laser light and magnetic fields to drive non-trivial quantum dynamics of a large spin-angular momentum associated with an atomic hyperfine ground state. The resulting nonlinear spin Hamiltonian is sufficiently general to achieve universal quantum control over the 2F+1 dimensional state space, and allows us to generate arbitrary spin states and perform a full quantum state reconstruction of the result. We have implemented and verified time optimal controls to generate a broad variety of spin states, as well as an adiabatic scheme to generate spin-squeezed states for metrology. Most recently we have used our control and measurement tools to realize a popular paradigm for quantum chaos known as the kicked top. Direct observation of the phase space dynamics of this system has given us an unprecedented look at quantum/classical correspondence. In the future we hope to extend our toolbox for control and measurement of individual atoms and to apply it also to collective spins. Applications include quantum metrology, quantum information processing and simulations of quantum manybody physics.