skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Microscopic theory of multiple-phonon-mediated dephasing and relaxation of quantum dots near a photonic band gap

Abstract

We derive a quantum theory of the role of acoustic and optical phonons in modifying the optical absorption line shape, polarization dynamics, and population dynamics of a two-level atom (quantum dot) in the ''colored'' electromagnetic vacuum of a photonic band-gap (PBG) material. This is based on a microscopic Hamiltonian describing both radiative and vibrational processes quantum mechanically. We elucidate the extent to which phonon-assisted decay limits the lifetime of a single photon-atom bound state and derive the modified spontaneous emission dynamics due to coupling to various phonon baths. We demonstrate that coherent interaction with undamped phonons can lead to an enhanced lifetime of a photon-atom bound state in a PBG. This results in reduction of the steady-state atomic polarization but an increase in the fractionalized upper state population in the photon-atom bound state. We demonstrate, on the other hand, that the lifetime of the photon-atom bound state in a PBG is limited by the lifetime of phonons due to lattice anharmonicities (breakup of phonons into lower energy phonons) and purely nonradiative decay. We also derive the modified polarization decay and dephasing rates in the presence of such damping. This leads to a microscopic, quantum theory of the optical absorption linemore » shapes. Our model and formalism provide a starting point for describing dephasing and relaxation in the presence of external coherent fields and multiple quantum dot interactions in electromagnetic reservoirs with radiative memory effects.« less

Authors:
;  [1]
  1. Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7 (Canada)
Publication Date:
OSTI Identifier:
21408318
Resource Type:
Journal Article
Journal Name:
Physical Review. A
Additional Journal Information:
Journal Volume: 81; Journal Issue: 2; Other Information: DOI: 10.1103/PhysRevA.81.023817; (c) 2010 The American Physical Society; Journal ID: ISSN 1050-2947
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ABSORPTION; ATOMS; BOUND STATE; DECAY; HAMILTONIANS; LIFETIME; PHONONS; PHOTONS; POLARIZATION; QUANTUM DOTS; RELAXATION; BOSONS; ELEMENTARY PARTICLES; MASSLESS PARTICLES; MATHEMATICAL OPERATORS; NANOSTRUCTURES; QUANTUM OPERATORS; QUASI PARTICLES; SORPTION

Citation Formats

Roy, Chiranjeeb, and John, Sajeev. Microscopic theory of multiple-phonon-mediated dephasing and relaxation of quantum dots near a photonic band gap. United States: N. p., 2010. Web. doi:10.1103/PHYSREVA.81.023817.
Roy, Chiranjeeb, & John, Sajeev. Microscopic theory of multiple-phonon-mediated dephasing and relaxation of quantum dots near a photonic band gap. United States. doi:10.1103/PHYSREVA.81.023817.
Roy, Chiranjeeb, and John, Sajeev. Mon . "Microscopic theory of multiple-phonon-mediated dephasing and relaxation of quantum dots near a photonic band gap". United States. doi:10.1103/PHYSREVA.81.023817.
@article{osti_21408318,
title = {Microscopic theory of multiple-phonon-mediated dephasing and relaxation of quantum dots near a photonic band gap},
author = {Roy, Chiranjeeb and John, Sajeev},
abstractNote = {We derive a quantum theory of the role of acoustic and optical phonons in modifying the optical absorption line shape, polarization dynamics, and population dynamics of a two-level atom (quantum dot) in the ''colored'' electromagnetic vacuum of a photonic band-gap (PBG) material. This is based on a microscopic Hamiltonian describing both radiative and vibrational processes quantum mechanically. We elucidate the extent to which phonon-assisted decay limits the lifetime of a single photon-atom bound state and derive the modified spontaneous emission dynamics due to coupling to various phonon baths. We demonstrate that coherent interaction with undamped phonons can lead to an enhanced lifetime of a photon-atom bound state in a PBG. This results in reduction of the steady-state atomic polarization but an increase in the fractionalized upper state population in the photon-atom bound state. We demonstrate, on the other hand, that the lifetime of the photon-atom bound state in a PBG is limited by the lifetime of phonons due to lattice anharmonicities (breakup of phonons into lower energy phonons) and purely nonradiative decay. We also derive the modified polarization decay and dephasing rates in the presence of such damping. This leads to a microscopic, quantum theory of the optical absorption line shapes. Our model and formalism provide a starting point for describing dephasing and relaxation in the presence of external coherent fields and multiple quantum dot interactions in electromagnetic reservoirs with radiative memory effects.},
doi = {10.1103/PHYSREVA.81.023817},
journal = {Physical Review. A},
issn = {1050-2947},
number = 2,
volume = 81,
place = {United States},
year = {2010},
month = {2}
}