Friday, 17 November, 2006
Gauging a Quantum Heat Bath with Dissipative Landau-Zener Transitions
M. Wubs, K. Saito, S. Kohler, P. Hänggi, Y. Kayanuma -
Phys. Rev. Lett. 97, 200404 (2006)
We calculate the exact Landau-Zener transition probabilities for a qubit with an arbitrary linear coupling to a bath at zero temperature. The final quantum state exhibits a peculiar entanglement between the qubit and the bath. In the special case of diagonal coupling, the bath does not influence the transition probability, whatever the speed of the Landau-Zener sweep. It is proposed to use Landau-Zener transitions to determine both the reorganization energy and the integrated spectral density of the bath. Possible applications include circuit QED and molecular nanomagnets.