1305.3872 (Alexandre Dauphin et al.)

Extracting the Chern number from the dynamics of a Fermi gas:
Implementing a quantum Hall bar for cold atoms    [PDF]

Alexandre Dauphin, Nathan Goldman

We propose a scheme to measure the quantized Hall conductivity of an ultracold Fermi gas initially prepared in a topological (Chern) insulating phase, and driven by a constant force. We show that the time evolution of the center of mass, after releasing the cloud, provides a direct and clear signature of the topologically invariant Chern number. We discuss the validity of this scheme, highlighting the importance of driving the system with a sufficiently strong force to displace the cloud over measurable distances while avoiding band-mixing effects. The unusual shapes of the driven atomic cloud are qualitatively discussed in terms of a semi-classical approach.

View original: http://arxiv.org/abs/1305.3872