Real-Space Mapping of Exciton Wave Functions in a Quantum Dot with Near-Field Optical Imaging Spectroscopy
T. Saiki a,b , K. Matsuda b,c S. Nomura d,e , M. Mihara e , Y. Aoyagi e,f , S. Nair g and T. Takagahara h
a Department of Electronics and Electrical Engineering, Keio University 3-14-1 Hiyoshi, Kohoku, Yokohama, Kanagawa 223-8522, Japan
b Kanagawa Academy of Science and Technology, Japan c PRESTO Japan Science and Technology Corporation (JST), Japan
d University of Tsukuba, Japan
e Institute of Physical and Chemical Research (RIKEN), Japan
f Tokyo Institute of Technology, Japan g University of Toronto, Canada,
h Kyoto Institute of Technology, Japan
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An exciton confined within a quantum dot acts as a two-level quantum system, and is one of the most promising candidates for quantum computing and quantum information processing. The real-space optical probing of the quantum eigenstates in a single quantum dot and coupled quantum dots should be developed toward the realization of quantum photonic devices, where their wave functions are dynamically controlled by coherent optical techniques. Here we apply near-field photoluminescence imaging spectroscopy with a high spatial resolution of 30nm to map out the centre-of-mass wave function of an exciton confined in a GaAs quantum dot. The spatial profile of the exciton emission, which reflects the shape of a monolayer-high island, differs from that of biexciton emission, due to different distributions of the polarization field for the exciton and biexciton recombinations.
DOI: 10.12693/APhysPolA.104.281
PACS numbers: 78.55.Cr, 78.67.Hc