W. D. Rice, S. Zybell, S. Winnerl, H. Schneider, M. Helm, L. Schneebeli, B. Breddermann, M. Kira, S. W. Koch, J. Kono
Using intense and narrow-bandwidth terahertz pulses, we demonstrate the manipulation of exciton populations and intra-excitonic dynamics in semiconductor quantum wells. The terahertz radiation quenches the 1s emission, which is followed by an enhancement and subsequent decay of 2s emission. The quenched 1s emission eventually becomes enhanced, finally decreasing to its unperturbed value, a demonstration of excitonic shelving. We develop a microscopic theory and show that the diffusive Coulomb scattering between the 2p and 2s states produces a symmetry breaking, leading to a terahertz-field-induced 1s-to-2s exciton population transfer.
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http://arxiv.org/abs/1203.3994
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