Creation of a squeezed photon distribution using artificial atoms with broken inversion symmetry
Martin Koppenhöfer, Michael Marthaler · Physical Review A · 2016
We consider a two-level system with both a transversal and a longitudinal coupling to the electromagnetic field of a resonator. Using a polaron transformation, this Hamiltonian can be mapped onto a Jaynes-Cummings Hamiltonian with generalized field operators acting on the electromagnetic field in the resonator. In contrast to the usual ladder operators $a$ and ${a}^{\ifmmode\dagger\else\textdagger\fi{}}$, these operators exhibit a nonmonotonous coupling strength with respect to the number $n$ of photons in the resonator. In particular, there are roots of the coupling between qubit and resonator at certain photon numbers ${n}_{0}$. We show that this effect can be exploited to generate photon-number squeezed light, characterized by a Fano factor $F\ensuremath{\ll}1$, with a large number of photons (e.g., of the order of $1\ifmmode\times\else\texttimes\fi{}{10}^{4}$).