Entanglement generation and detection in split exciton-polariton condensates

We propose a method of generating and detecting spatially defined entanglement in exciton-polariton condensates at steady state. In our scheme we first create a spinor polariton condensate, such that steady-state squeezing is obtained under a one-axis twisting interaction. Then the condensate is split either physically or virtually, which results in entanglement generated between the two parts. A virtual split means that the condensate is not physically split, but its near-field image is divided into two parts, and the spin correlations are deduced from polarization measurements in each half. We theoretically model and examine the logarithmic negativity criterion and several correlation-based criteria to show that entanglement exists under experimentally achievable parameters.