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Title: Linewidth broadening and tunneling of excitons bound to N pairs in dilute GaAs:N

Abstract

The exciton bound to a pair of nitrogen atoms situated at nearby lattice sites in dilute GaAs:N provides an energetically uniform electronic system, spectrally distinct from pairs with larger or smaller separations, and can even be grown with a uniform pair orientation in the crystal. We use photoluminescence excitation spectroscopy on an ensemble of N pairs to study the narrow continuous energy distribution within two of the individual exchange- and symmetry-split exciton states. Inhomogeneous linewidths of 50-60 ueV vary across the crystal on a mesoscopic scale and can be 30 ueV at microscopic locations indicating that the homogeneous linewidth inferred from previous time-domain measurements is still considerably broadened. While excitation and emission linewidths are similar, results show a small energy shift between them indicative of exciton transfer via phonon-assisted tunneling between spatially separated N pairs. We numerically simulate the tunneling in a spatial network of randomly distributed pairs having a normal distribution of bound exciton energies. Comparing the ensemble excitation-emission energy shift with the measured results shows that the transfer probability is higher than expected from the dilute pair concentration and what is known of the exciton wavefunction spatial extent. Both the broadening and the exciton transfer have implications formore » the goal of pair-bound excitons as a single- or multi-qubit system.« less

Authors:
 [1];  [1];  [1];  [2];  [2]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  2. Phillips-Univ., Renthof (Germany)
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1508957
Alternate Identifier(s):
OSTI ID: 1505663
Report Number(s):
NREL/JA-5K00-73378
Journal ID: ISSN 0021-8979
Grant/Contract Number:  
AC36-08GO28308
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 125; Journal Issue: 14; Journal ID: ISSN 0021-8979
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; atomic and molecular spectra; excitation energies; photoluminescence excitation spectroscopy; semiconductors; excitons; phonons; photoluminescence spectroscopy; quantum computing

Citation Formats

Fluegel, B., Beaton, D. A., Alberi, K., Volz, K., and Stolz, W. Linewidth broadening and tunneling of excitons bound to N pairs in dilute GaAs:N. United States: N. p., 2019. Web. doi:10.1063/1.5086181.
Fluegel, B., Beaton, D. A., Alberi, K., Volz, K., & Stolz, W. Linewidth broadening and tunneling of excitons bound to N pairs in dilute GaAs:N. United States. doi:10.1063/1.5086181.
Fluegel, B., Beaton, D. A., Alberi, K., Volz, K., and Stolz, W. Mon . "Linewidth broadening and tunneling of excitons bound to N pairs in dilute GaAs:N". United States. doi:10.1063/1.5086181.
@article{osti_1508957,
title = {Linewidth broadening and tunneling of excitons bound to N pairs in dilute GaAs:N},
author = {Fluegel, B. and Beaton, D. A. and Alberi, K. and Volz, K. and Stolz, W.},
abstractNote = {The exciton bound to a pair of nitrogen atoms situated at nearby lattice sites in dilute GaAs:N provides an energetically uniform electronic system, spectrally distinct from pairs with larger or smaller separations, and can even be grown with a uniform pair orientation in the crystal. We use photoluminescence excitation spectroscopy on an ensemble of N pairs to study the narrow continuous energy distribution within two of the individual exchange- and symmetry-split exciton states. Inhomogeneous linewidths of 50-60 ueV vary across the crystal on a mesoscopic scale and can be 30 ueV at microscopic locations indicating that the homogeneous linewidth inferred from previous time-domain measurements is still considerably broadened. While excitation and emission linewidths are similar, results show a small energy shift between them indicative of exciton transfer via phonon-assisted tunneling between spatially separated N pairs. We numerically simulate the tunneling in a spatial network of randomly distributed pairs having a normal distribution of bound exciton energies. Comparing the ensemble excitation-emission energy shift with the measured results shows that the transfer probability is higher than expected from the dilute pair concentration and what is known of the exciton wavefunction spatial extent. Both the broadening and the exciton transfer have implications for the goal of pair-bound excitons as a single- or multi-qubit system.},
doi = {10.1063/1.5086181},
journal = {Journal of Applied Physics},
number = 14,
volume = 125,
place = {United States},
year = {2019},
month = {4}
}

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This content will become publicly available on April 8, 2020
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