1212.5864 (C. K. Law)

Switchable vacuum Rabi oscillations induced by virtual photons in the
ultrastrong coupling regime    [PDF]

C. K. Law

We investigate a dynamical effect of virtual photons carried by the vacuum dressed ground state in the ultrastrong coupling regime. By coupling the ground state to an auxiliary atomic level $|f>$ via an external classical driving field, we show that the system can execute a kind of vacuum Rabi oscillations in which the system makes a transition to $|f>$ accompanied by the emission of a real single photon. In particular, the effective vacuum Rabi frequency is proportional to the amplitude of a single virtual photon in the ground state. The effect thus provides a way to probe the ground state structure in the ultrastrong coupling regime.

View original: http://arxiv.org/abs/1212.5864