Phonon Decoherence of Quantum Dots in Photonic Structures: Broadening of the ZeroPhonon Line and the Role of Dimensionality
Abstract
We develop a general microscopic theory describing the phonon decoherence of quantum dots and indistinguishability of the emitted photons in photonic structures. The coherence is found to depend fundamentally on the dimensionality of the structure resulting in vastly different performance for quantum dots embedded in a nanocavity (0D), waveguide (1D), slab (2D), or bulk medium (3D). In bulk, we find a striking temperature dependence of the dephasing rate scaling as T^{11} implying that phonons are effectively "frozen out" for T ≲4 K . The phonon density of states is strongly modified in 1D and 2D structures leading to a linear temperature scaling for the dephasing strength. The resulting impact on the photon indistinguishability can be important even at subKelvin temperatures. Our findings provide a comprehensive understanding of the fundamental limits to photon indistinguishability in photonic structures.
 Publication:

Physical Review Letters
 Pub Date:
 June 2018
 DOI:
 10.1103/PhysRevLett.120.257401
 arXiv:
 arXiv:1702.04812
 Bibcode:
 2018PhRvL.120y7401T
 Keywords:

 Condensed Matter  Mesoscale and Nanoscale Physics;
 Physics  Optics;
 Quantum Physics
 EPrint:
 19 pages, 9 figures