Nonreciprocal Entanglement and Blockade Between Two Qubits in a Spinning Cavity QED System

A method is proposed to simultaneously achieve nonreciprocal entanglement and nonreciprocal dipole blockade in a spinning cavity QED system, where two qubits are subjected to dipole-dipole interaction and coupled to a cavity mode. It is found that the entanglement and the dipole blockade prominently manifest in a chosen direction, while completely vanishing in the other. Remarkably, the perfect nonreciprocal entanglement and dipole blockade can be generated. This nonreciprocity results from Sagnac effect, which leads to different quantum interference effects in the opposite direction. The work provides an all-optical manipulation method for controlling the entanglement and the dipole blockade, which may have potential applications in the implementation of chiral networks and backaction-immune quantum sensors.