The Experts below are selected from a list of 1890 Experts worldwide ranked by ideXlab platform
A M Fox - One of the best experts on this subject based on the ideXlab platform.
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phonon assisted population inversion of a single ingaas gaas quantum dot by pulsed laser excitation
Physical Review Letters, 2015Co-Authors: J H Quilter, Alistair J Brash, Feng Liu, Martin Glassl, Andreas M Barth, Vollrath M Axt, A J Ramsay, M S Skolnick, A M FoxAbstract:We demonstrate a new method to realize the population inversion of a single InGaAs/GaAs quantum dot excited by a laser pulse tuned within the neutral exciton phonon sideband. In contrast to the conventional method of inverting a two-level system by performing coherent Rabi Oscillation, the inversion is achieved by rapid thermalization of the optically dressed states via incoherent phonon-assisted relaxation. A maximum exciton population of 0.67 ± 0.06 is measured for a laser tuned 0.83 meV to higher energy. Furthermore, the phonon sideband is mapped using a two-color pump-probe technique, with its spectral form and magnitude in very good agreement with the result of path-integral calculations.
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coherent response of a quantum dot exciton driven by a rectangular spectrum optical pulse
Physical Review B, 2007Co-Authors: A J Ramsay, A M Fox, R S Kolodka, Frank Bello, P W Fry, A Tahraoui, Huiyun Liu, M Hopkinson, D M Whittaker, M S SkolnickAbstract:We observe strong nonlinear absorption in the excitation profile of a single InGaAs quantum dot exciton driven by a rectangular spectrum optical pulse, in a region of detuning where the linear response is weak. Here the exciton is resonant with the temporal side-lobes of the pulse, which drive a damped Rabi Oscillation. Good agreement is found between experiment and a two-level atom model. In the nonlinear regime the excitation profile exhibits features from both the rectangular spectrum and the two peaks present in the spectrum of the autocorrelation of the pulse.
K Ensslin - One of the best experts on this subject based on the ideXlab platform.
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all microwave control and dispersive readout of gate defined quantum dot qubits in circuit quantum electrodynamics
Physical Review Letters, 2019Co-Authors: Pasquale Scarlino, D J Van Woerkom, Anna Stockklauser, Jonne V Koski, Michele C Collodo, Simone Gasparinetti, Christian Reichl, Werner Wegscheider, Thomas Ihn, K EnsslinAbstract:Developing fast and accurate control and readout techniques is an important challenge in quantum information processing with semiconductor qubits. Here, we study the dynamics and the coherence properties of a GaAs/AlGaAs double quantum dot charge qubit strongly coupled to a frequency-tunable high-impedance resonator. We drive qubit transitions with synthesized microwave pulses and perform qubit readout through the state-dependent frequency shift imparted by the qubit on the dispersively coupled resonator. We perform Rabi Oscillation, Ramsey fringe, energy relaxation, and Hahn-echo measurements and find significantly reduced decoherence rates down to γ_{2}/2π∼3 MHz corresponding to coherence times of up to T_{2}∼50 ns for charge states in gate-defined quantum dot qubits. We realize Rabi π pulses of width down to σ∼0.25 ns.
Katharina Rojan - One of the best experts on this subject based on the ideXlab platform.
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enhanced second order nonlinearity for thz generation by resonant interaction of exciton polariton Rabi Oscillations with optical phonons
Physical Review Letters, 2017Co-Authors: Katharina Rojan, Yoan Leger, Giovanna Morigi, Maxime Richard, Anna MinguzziAbstract:Semiconductor microcavities in the strong-coupling regime exhibit an energy scale in the terahertz (THz) frequency range, which is fixed by the Rabi splitting between the upper and lower exciton-polariton states. While this range can be tuned by several orders of magnitude using different excitonic media, the transition between both polaritonic states is dipole forbidden. In this work, we show that, in cadmium telluride microcavities, the Rabi-Oscillation-driven THz radiation is actually active without the need for any change in the microcavity design. This feature results from the unique resonance condition which is achieved between the Rabi splitting and the phonon-polariton states and leads to a giant enhancement of the second-order nonlinearity.
H. Ando - One of the best experts on this subject based on the ideXlab platform.
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exciton Rabi Oscillation in single quantum dot temporal measurement of Oscillation and corresponding energy level splitting
Conference on Lasers and Electro-Optics, 2001Co-Authors: Haruhiko Kamada, Toshihide Takagahara, H. Ando, Jiro TemmyoAbstract:A spectroscopic method, which enables characterization of a single isolated quantum dot and quantum wave function interferometry is applied to exciton discrete excited state in InGaAs quantum dot. Long coherence of zero-dimensional excitonic states made possible the observe coherent population flopping in a 0D excitonic two-level system in a time-domain interferometric measurement and corresponding energy splitting is also manifested in an energy-domain measurement.
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Exciton Rabi Oscillation in a single quantum dot
Physical Review Letters, 2001Co-Authors: Haruhiko Kamada, Hiroaki Gotoh, Toshihide Takagahara, Jiro Temmyo, H. AndoAbstract:A spectroscopic method, which enables characterization of a single isolated quantum dot and a quantum wave function interferometry, is applied to an exciton discrete excited state in an InGaAs quantum dot. Long coherence of zero-dimensional excitonic states made possible the observation of coherent population flopping in a 0D excitonic two-level system in a time-domain interferometric measurement. Corresponding energy splitting is also manifested in an energy-domain measurement.
Stephen H Hughes - One of the best experts on this subject based on the ideXlab platform.
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polaron master equation theory of pulse driven phonon assisted population inversion and single photon emission from quantum dot excitons
Physical Review B, 2016Co-Authors: Ross Manson, Kaushik Roychoudhury, Stephen H HughesAbstract:We introduce an intuitive and semianalytical polaron master equation approach to model pulse-driven population inversion and emitted single photons from a quantum dot exciton. The master equation theory allows one to identify important phonon-induced scattering rates analytically and fully includes the role of the time-dependent pump field. As an application of the theory, we first study a quantum dot driven by a time-varying laser pulse on and off resonance, showing the population inversion caused by acoustic phonon emission in direct agreement with recent experiments of Quilter et al. [Phys. Rev. Lett. 114, 137401 (2015)]. We then model quantum dots in weakly coupled cavities and show the difference in population response between exciton-driven and cavity-driven systems. Finally, we assess the nonresonant phonon-assisted loading scheme with a quantum dot resonantly coupled to a cavity as a deterministic single-photon source. We also compare and contrast the important single photon figures of merit with direct Rabi Oscillation of the population using a resonant $\ensuremath{\pi}$ pulse, and show that the resonant scheme is much more efficient.
