First-Order Quantum Phase Transition for Dicke Model Induced by Atom-Atom Interaction

Zhao Xiu-Qin^{1, 2}, Liu Ni^{1, †}, Liang Jiu-Qing¹

(Color online) Phase diagram in g-q space. The NP with belongs to the normal phase. The SP with is the right region of the boundary line g_cq. The color index indicates the photon number .