Abstract

Several applications in quantum information processing, such as quantum repeaters and quantum networks, require the quantum state of a photon to be mapped onto a stable quantum memory in a reversible manner [1, 2]. A semiconductor quantum dot (QD) functions as an effective quantum interface between light and matter where the polarisation of a single photon can be transcribed into the spin state of a photo generated exciton with high fidelity [3]. However, the short lifetime of an exciton confined in a single QD, ~1ns, does not allow that quantum information to be stored for any extended period of time unless the electron and hole are dissociated and stored in separate reservoirs. It has been shown that for spatially indirect excitons, where the electron and hole are confined in the two separate QDs of a quantum dot molecule (QDM), the lifetime can be increased several orders of magnitude [4].

© 2011 IEEE