Excitation-Induced Dephasing in a Resonantly DrivenInAs/GaAsQuantum Dot

Abstract

We report on coherent emission of the neutral exciton state in a single semiconductor self-assembled InAs/GaAs quantum dot embedded in a one-dimensional waveguide, under resonant picosecond pulsed excitation. Direct measurements of the radiative lifetime and coherence time are performed as a function of excitation power and temperature. The characteristic damping of Rabi oscillations observed is attributed to an excitation-induced dephasing due to a resonant coupling between the emitter and the acoustic phonon bath of the matrix. Other sources responsible for the decrease of the coherence time have been evidenced, in particular an enhancement of the radiative recombination rate due to the resonant strong coupling between the dot and the one-dimensional optical mode. As a consequence, the emission couples very efficiently into the waveguide mode, leading to an additional relaxation term of the excited-state population.

Temperature-Dependent Mollow Triplet Spectra from a Single Quantum Dot: Rabi Frequency Renormalization and Sideband Linewidth Insensitivity

“…As the intensity of the pump laser increases, however, an additional power dependent dephasing contribution arises, even at low temperatures [14][15][16][17][18][19][20][21][22][23][24]. This is often termed excitation induced dephasing (EID), which commonly originates from deformation potential coupling of QD excitons to longitudinal acoustic (LA) phonons.…”

“…Indistinguishable photons can be produced by s-shell resonant optical excitation of a single QD [10][11][12], wherein an electron-hole pair is created directly without any relaxation from higher states, which would otherwise cause inhomogeneous broadening in the QD emission spectrum. The coherence time (T 2 ) of such photons is able to approach the Fourier transform limit, T 2 ¼ 2T 1 (with T 1 the QD radiative lifetime) at low temperatures (∼4 K) and weak driving strengths [13].As the intensity of the pump laser increases, however, an additional power dependent dephasing contribution arises, even at low temperatures [14][15][16][17][18][19][20][21][22][23][24]. This is often termed excitation induced dephasing (EID), which commonly originates from deformation potential coupling of QD excitons to longitudinal acoustic (LA) phonons.…”

“…[14,15], where QD excitonic Rabi oscillations were measured via photocurrents, and in Refs. [16,17] through driven QD optical emission.Besides EID, another direct manifestation of the phonon influence on a driven dot can be found in the dependence of its properties on temperature. In fact, an idealized two-level system (e.g., an isolated atom) should not show any change in emission behavior with temperature over the usual experimental range, in contrast to the response to changes PRL 113,…”

The role of phonons for exciton and biexciton generation in an optically driven quantum dot

“…Since then, many other experiments have been performed and nowadays Rabi rotations are commonly used in many optical control experiments [157,158,159,160,161,162,54,53,148,163,164].…”

Engineering a squeezed phonon reservoir with a bichromatic driving of a quantum dot

“…A number of different situations have been investigated [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. These include experimental studies of the effect of phonons on the Rabi oscillations, Autler-Townes splitting, and the Mollow triplet of the fluorescence field emitted by a driven quantum dot [16][17][18][19][20][21][22][23][24].…”