Qubit-induced strong Wigner negativity at steady state
We show that a Kerr-nonlinear cavity coupled to an incoherently pumped two-level qubit can stabilize a nonclassical steady state with pronounced Wigner negativity. Without the qubit, two-photon drive and dissipation preserve photon-number parity and confine vacuum-initiated dynamics to the even-parity Fock subspace, pr...