Influence of electron-phonon scattering for an on-demand quantum dot single-photon source using cavity-assisted adiabatic passage

A quantum dot coupled to an optical cavity has recently proven to be an excellent source of ondemand single photons. Typically, applications require simultaneous high efficiency of the source and quantum indistinguishability of the extracted photons. While much progress has been made both in suppressing background sources of decoherence and utilizing cavity-quantum electrodynamics to overcome fundamental limitations set by the intrinsic exciton-phonon scattering inherent in the solid-state platform, the role of the excitation pulse has been often neglected. We investigate quantitatively the factors associated with pulsed excitation that can limit simultaneous efficiency and indistinguishability, including excitation of multiple excitons, multi-photons, and pump-induced dephasing, and find for realistic single photon sources that these effects cause degradation of the source figures-of-merit comparable to that of phonon scattering. We also develop rigorous open quantum system polaron master equation models of quantum dot dynamics under a time-dependent drive which incorporate non-Markovian effects of both photon and phonon reservoirs, and explicitly show how coupling to a high Q-factor cavity suppresses multi-photon emission in a way not predicted by commonly employed models. We then use our findings to summarize the criteria that can be used for single photon source optimization.

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“…which has been previously used to analyze pulse-driven phonon-exciton scattering in biexciton systems [26].…”

Section: And the Interaction Hamiltonian Be-mentioning

confidence: 99%

Pulsed excitation dynamics in quantum-dot–cavity systems: Limits to optimizing the fidelity of on-demand single-photon sources

Gustin

Hughes

2018

Phys. Rev. B

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“…Finally, we note that while our theory only considered situations in which the system of interest underwent Hamiltonian evolution, an exciting avenue for further research would be the possible extension of this work to directly computing N -photon scattering super-operators under the addition of dissipation. For instance, phonon-induced dephasing is an important consideration in the solid state [101][102][103], where a computation of the single-photon density matrix of the output field directly in the presence of this dephasing would be quite valuable. We believe that our framework constitutes a compelling argument to reconsider the dynamics of photon emission in a temporal mode basis and provides a way to answer many interesting questions going forwards.…”

Section: Discussionmentioning

confidence: 99%

“…We can carry out a similar procedure for the case where j m < P (as in Eqs. [92][93][94][95][96][97][98][99][100][101][102][103]. Here, we obtain…”

Section: Energy Non-conservingmentioning

confidence: 99%

Scattering into one-dimensional waveguides from a coherently-driven quantum-optical system

Fischer

Trivedi

Ramasesh

et al. 2018

Quantum

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We develop a new computational tool and framework for characterizing the scattering of photons by energy-nonconserving Hamiltonians into unidirectional (chiral) waveguides, for example, with coherent pulsed excitation. The temporal waveguide modes are a natural basis for characterizing scattering in quantum optics, and afford a powerful technique based on a coarse discretization of time. This overcomes limitations imposed by singularities in the waveguide-system coupling. Moreover, the integrated discretized equations can be faithfully converted to a continuous-time result by taking the appropriate limit. This approach provides a complete solution to the scattered photon field in the waveguide, and can also be used to track system-waveguide entanglement during evolution. We further develop a direct connection between quantum measurement theory and evolution of the scattered field, demonstrating the correspondence between quantum trajectories and the scattered photon state. Our method is most applicable when the number of photons scattered is known to be small, i.e. for a single-photon or photon-pair source. We illustrate two examples: analytical solutions for short laser pulses scattering off a two-level system and numerically exact solutions for short laser pulses scattering off a spontaneous parametric downconversion (SPDC) or spontaneous four-wave mixing (SFWM) source. Finally, we note that our technique can easily be extended to systems with multiple ground states and generalized scattering problems with both finite photon number input and coherent state drive, potentially enhancing the understanding of, e.g., light-matter entanglement and photon phase gates.Numerical package in collaboration with Ben Bartlett (Stanford University), implemented in QuTiP: The Quantum Toolbox in Python [1] with tutorial notebook numerically reproducing results shown in this paper. Photon flux and interpretation of temporal modes 34 B Second-order coherence with temporal modes 35 C Mollow transformation 36Accepted in Quantum 2018-05-17, click title to verify

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“…Examples are the phonon-induced damping of Rabi rotations in the case of resonant driving of the QD [3], chirp-dependent phonon damping of the adiabatic rapid passage induced by chirped laser pulses [4][5][6], phonon-assisted state preparation by detuned excitation [7][8][9][10][11] and the polarization decay in four-wave mixing signals [12,13]. Also for QDs coupled to a quantized cavity light field phonons play an important role [14][15][16][17][18]. To theoretically simulate the phonon influence different theoretical approaches have been developed, identifying the coupling to longitudinal acoustic (LA) phonons as typically being the dominant mechanism.…”

Section: Introductionmentioning

confidence: 99%

Phonon impact on optical control schemes of quantum dots: Role of quantum dot geometry and symmetry

2017

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Phonons strongly influence the optical control of semiconductor quantum dots. When modeling the electron-phonon interaction in several theoretical approaches the quantum dot geometry is approximated by a spherical structure, though typical self-assembled quantum dots are strongly lens-shaped. By explicitly comparing simulations of a spherical and a lens-shaped dot using a wellestablished correlation expansion approach we show that indeed lens-shaped dots can be exactly mapped to a spherical geometry when studying the phonon influence on the electronic system. We also give a recipe to reproduce spectral densities from more involved dots by rather simple spherical models. On the other hand, breaking the spherical symmetry has a pronounced impact on the spatio-temporal properties of the phonon dynamics. As an example we show that for a lens-shaped quantum dot the phonon emission is strongly concentrated along the direction of the smallest axis of the dot which is important for the use of phonons for the communication between different dots.

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Influence of electron-phonon scattering for an on-demand quantum dot single-photon source using cavity-assisted adiabatic passage

Cited by 21 publications

References 67 publications

Pulsed excitation dynamics in quantum-dot–cavity systems: Limits to optimizing the fidelity of on-demand single-photon sources

Pulsed excitation dynamics in quantum-dot–cavity systems: Limits to optimizing the fidelity of on-demand single-photon sources

Scattering into one-dimensional waveguides from a coherently-driven quantum-optical system

Phonon impact on optical control schemes of quantum dots: Role of quantum dot geometry and symmetry

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