Continuous entanglement generating superradiant SU(4) laser

We present a cross-cavity system in which steady-state superradiance is achieved with solely collective dissipative dynamics. The cavities symmetrically couple an ensemble of four-level atoms by driving transitions between two electronic and two motional states. We demonstrate that the system continuously generates both interparticle entanglement between the constituent particles and intraparticle entanglement between the internal and external degrees of freedom. We use innovative techniques to examine the two types of entanglement and, remarkably, we find that the system in steady-state is Heisenberg limit scaled with nearly maximal entanglement entropy between the internal and external degrees of freedom. Lastly, we discuss potential applications of our proposed model to the prominent fields of quantum metrology and quantum information science.