Strong quantum coherence between fermi liquid Mahan excitons

Academic Article

Abstract

  • © 2016 American Physical Society. In modulation doped quantum wells, the excitons are formed as a result of the interactions of the charged holes with the electrons at the Fermi edge in the conduction band, leading to the so-called "Mahan excitons." The binding energy of Mahan excitons is expected to be greatly reduced and any quantum coherence destroyed as a result of the screening and electron-electron interactions. Surprisingly, we observe strong quantum coherence between the heavy hole and light hole excitons. Such correlations are revealed by the dominating cross-diagonal peaks in both one-quantum and two-quantum two-dimensional Fourier transform spectra. Theoretical simulations based on the optical Bloch equations where many-body effects are included phenomenologically reproduce well the experimental spectra. Time-dependent density functional theory calculations provide insight into the underlying physics and attribute the observed strong quantum coherence to a significantly reduced screening length and collective excitations of the many-electron system.
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    Digital Object Identifier (doi)

    Author List

  • Paul J; Stevens CE; Liu C; Dey P; McIntyre C; Turkowski V; Reno JL; Hilton DJ; Karaiskaj D
  • Volume

  • 116
  • Issue

  • 15