Abstract
A nondestructive parity-check detector (PCD) scheme for two single-electron quantum dots embedded in double-sided optical microcavities is presented here. Using a polarization-entangled photon pair, the PCD works in a parallel style and is robust to the phase fluctuation of the optical path length. In addition, based on this nondestructive PCD, an economic entanglement purification protocol for electron pairs is presented. The parties in quantum communication can increase the purification efficiency and simultaneously decrease the quantum source consumed for some particular fidelity thresholds. Therefore, this protocol has good applications in the future quantum communication and distributed quantum networks.