Physical Review B
Two-photon absorption by a quantum dot pair
Michael Scheibner, Sophia E. Economou, Ilya V. Ponomarev, Cameron V. Jennings, Allan S. Bracker, D. Gammon
Abstract
The biexciton absorption spectrum of a pair of InAs/GaAs quantum dots is being studied by photoluminescence excitation spectroscopy. An absorption resonance with the characteristics of an instantaneous two-photon process reveals a coherent interdot two-photon transition. Pauli-selective tunneling is being used to demonstrate the transduction of the two-photon coherence into a nonlocal spin singlet state. The two-photon transition can be tuned spectrally by electric field, enabling amplification of its transition strength.