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15
Jun 27, 2018
06/18
by
Edward B. Flagg; Glenn S. Solomon
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We propose a method to read-out the spin-state of an electron in a quantum dot in a Voigt geometry magnetic field using cycling transitions induced by the AC Stark effect. We show that cycling transitions can be made possible by a red-detuned, circularly-polarized laser, which modifies the spin eigenstates and polarization selection rules via the AC Stark effect. A Floquet-Liouville supermatrix approach is used to calculate the time-evolution of the density matrix under the experimental...
Topics: Quantum Physics, Mesoscale and Nanoscale Physics, Condensed Matter
Source: http://arxiv.org/abs/1505.06172
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122
Jul 22, 2013
07/13
by
Andreas Muller; Wei Fang; John Lawall; Glenn S. Solomon
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The photoluminescence spectrum of a single quantum dot was recorded as a secondary resonant laser optically dressed either the vacuum-to-exciton or the exciton-to-biexciton transitions. High-resolution polarization-resolved measurements using a scanning Fabry-Perot interferometer reveal splittings of the linearly-polarized fine-structure states that are non-degenerate in an asymmetric quantum dot. These splittings manifest as either triplets or doublets and depend sensitively on laser intensity...
Source: http://arxiv.org/abs/0807.0043v1
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52
Sep 21, 2013
09/13
by
Michael Metcalfe; Andreas Muller; Glenn S. Solomon; John Lawall
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We present a detailed study of the use of Fabry-Perot (FP) cavities for the spectroscopy of single InAs quantum dots (QDs). We derive optimal cavity characteristics and resolution limits, and measure photoluminescence linewidths as low as 0.9 GHz. By embedding the QDs in a planar cavity, we obtain a sufficiently large signal to actively feed back on the length of the FP to lock to the emission of a single QD with a stability below 2% of the QD linewidth. An integration time of approximately two...
Source: http://arxiv.org/abs/1008.2341v1
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89
Sep 17, 2013
09/13
by
Charles Santori; Glenn S. Solomon; Matthew Pelton; Yoshihisa Yamamoto
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The multi-excitonic decay process in a single InAs quantum dot is studied through high-resolution time-resolved spectroscopy. A cascaded emission sequence involving three spectral lines is seen that is described well over a wide range of pump powers by a simple model. The measured biexcitonic decay rate is about 1.5 times the single-exciton decay rate. This ratio suggests the presence of selection rules, as well as a significant effect of the Coulomb interaction on the biexcitonic wavefunction.
Source: http://arxiv.org/abs/cond-mat/0108466v3
3
3.0
Jun 29, 2018
06/18
by
Tobias Huber; Ana Predojević; Glenn S. Solomon; Gregor Weihs
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In this paper we investigate the coherence properties of a quantum dot under two-photon resonant excitation in combination with an additional photo-neutralization laser. The photo-neutralization increases the efficiency of the excitation process and thus, the brightness of the source, by a factor of approximately 1.5 for biexciton-exciton pairs. This enhancement does not degrade the relevant coherences in the system; neither the single photon coherence time, nor the coherence of the excitation...
Topics: Mesoscale and Nanoscale Physics, Quantum Physics, Condensed Matter
Source: http://arxiv.org/abs/1603.09085
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132
Jul 20, 2013
07/13
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Deepak Sridharan; Ranojoy Bose; Hyochul Kim Glenn S. Solomon; Edo Waks
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We experimentally investigate the dynamic nonlinear response of a single quantum dot (QD) strongly coupled to a photonic crystal cavity-waveguide structure. The temporal response is measured by pump-probe excitation where a control pulse propagating through the waveguide is used to create an optical Stark shift on the QD, resulting in a large modification of the cavity reflectivity. This optically induced cavity reflectivity modification switches the propagation direction of a detuned signal...
Source: http://arxiv.org/abs/1107.3751v1
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36
Sep 18, 2013
09/13
by
Edward B. Flagg; Sergey V. Polyakov; Tim Thomay; Glenn S. Solomon
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We measure the dynamics of a non-classical optical field using two-time second-order correlations in conjunction with pulsed excitation. The technique quantifies single-photon purity and coherence during the excitation-decay cycle of an emitter, illustrated here using a quantum dot. We observe that for certain pump wavelengths, photons detected early in the cycle have reduced single-photon purity and coherence compared to those detected later. A model indicates that the single-photon purity...
Source: http://arxiv.org/abs/1209.3652v1
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8.0
Jun 29, 2018
06/18
by
Disheng Chen; Gary R. Lander; Glenn S. Solomon; Edward B. Flagg
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Resonant photoluminescence excitation (RPLE) spectra of a neutral InGaAs quantum dot show an unconventional line-shape that depends on the detection polarization. We characterize this phenomenon by performing polarization-dependent RPLE measurements and simulating the measured spectra with a 3-level quantum model. This analysis enables us to extract the coherence between the two exciton states from the measured spectra. The good agreement between the data and model indicates that the...
Topics: Mesoscale and Nanoscale Physics, Condensed Matter
Source: http://arxiv.org/abs/1610.06963
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39
Sep 22, 2013
09/13
by
Charles Santori; David Fattal; Matthew Pelton; Glenn S. Solomon; Yoshihisa Yamamoto
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Polarization correlation in a linear basis, but not entanglement, is observed between the biexciton and single-exciton photons emitted by a single InAs quantum dot in a two-photon cascade. The results are well described quantitatively by a probabilistic model that includes two decay paths for a biexciton through a non-degenerate pair of one-exciton states, with the polarization of the emitted photons depending on the decay path. The results show that spin non-degeneracy due to quantum-dot...
Source: http://arxiv.org/abs/cond-mat/0111242v2
3
3.0
Jun 30, 2018
06/18
by
Seng Fatt Liew; Brandon Redding; Li Ge; Glenn S. Solomon; Hui Cao
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We demonstrate lasing mode selection in nearly circular semiconductor microdisks by shaping the spatial profile of optical pump. Despite of strong mode overlap, adaptive pumping suppresses all lasing modes except the targeted one. Due to slight deformation of the cavity shape and boundary roughness, each lasing mode has distinct emission pattern. By selecting different mode to be the dominant lasing mode, we can switch both the lasing frequency and the output direction. Such tunability by...
Topics: Physics, Optics
Source: http://arxiv.org/abs/1404.6709
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41
Sep 22, 2013
09/13
by
Hyochul Kim; Thomas C. Shen; Deepak Sridharan; Glenn S. Solomon; Edo Waks
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We apply magnetic fields of up to 7 T to an indium arsenide (InAs) quantum dot (QD) strongly coupled to a photonic crystal cavity. The field lifts the degeneracy of QD exciton spin states, and tune their emission energy by a combination of diamagnetic and Zeeman energy shifts. We use magnetic field tuning to shift the energies of the two spin states to be selectively on resonance with the cavity. Strong coupling between the cavity and both spin states is observed. Magnetic field tuning enables...
Source: http://arxiv.org/abs/1101.0749v1
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60
Sep 21, 2013
09/13
by
Michael Metcalfe; Stephen M. Carr; Andreas Muller; Glenn S. Solomon; John Lawall
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The dynamic response of InAs/GaAs self-assembled quantum dots (QDs) to strain is studied experimentally by periodically modulating the QDs with a surface acoustic wave and measuring the QD fluorescence with photoluminescence and resonant spectroscopy. When the acoustic frequency is larger than the QD linewidth, we resolve phonon sidebands in the QD fluorescence spectrum. Using a resonant pump laser, we have demonstrated optical frequency conversion via the dynamically modulated QD, which is the...
Source: http://arxiv.org/abs/1008.2342v1
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58
Sep 19, 2013
09/13
by
Hui Deng; Glenn S. Solomon; Rudolf Hey; Klaus H. Ploog; Yoshihisa Yamamoto
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We perform Young's double-slit experiment to study the spatial coherence properties of a two-dimensional dynamic condensate of semiconductor microcavity polaritons. The coherence length of the system is measured as a function of the pump rate, which confirms a spontaneous buildup of macroscopic coherence in the condensed phase. An independent measurement reveals that the position and momentum uncertainty product of the condensate is close to the Heisenberg limit. An experimental realization of...
Source: http://arxiv.org/abs/cond-mat/0703508v2
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45
Sep 19, 2013
09/13
by
Andreas Muller; Edward B. Flagg; Michael Metcalfe; John Lawall; Glenn S. Solomon
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eye 45
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We report the coupling of individual InAs quantum dots (QDs) to an external-mirror microcavity. The external mirror is bonded to a fiber and positioned above a semiconductor sample consisting of a QD-containing GaAs layer on top of a distributed Bragg reflector (DBR). This open cavity can be rapidly tuned with a piezoelectric actuator without negatively affecting the QD linewidth. A mirror radius of curvature of 42 microns and a cavity length of 10 microns enable good mode-matching and thus...
Source: http://arxiv.org/abs/0910.4658v1
7
7.0
Jun 30, 2018
06/18
by
Seng Fatt Liew; Li Ge; Brandon Redding; Glenn S. Solomon; Hui Cao
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eye 7
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We demonstrate an effective control of nonlinear interactions of lasing modes in a semiconductor microdisk cavity by shaping the pump profile. A target mode is selected at the expense of its competing modes either by increasing their lasing thresholds or suppressing their power slopes above the lasing threshold. Despite of strong spatial overlap of the lasing modes at the disk boundary, adaptive pumping enables an efficient selection of any lasing mode to be the dominant one, leading to a...
Topics: Physics, Optics
Source: http://arxiv.org/abs/1412.8513
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52
Sep 18, 2013
09/13
by
Brandon Redding; Li Ge; Qinghai Song; Jan Wiersig; Glenn S. Solomon; Hui Cao
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eye 52
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The local chiral symmetry between clockwise (CW) and counter-clockwise (CCW) propagating light in a deformed microcavity can be broken by wave optics effects, which become significant as the cavity size approaches the wavelength. We show that the spatial separation of the CW and CCW ray orbits underlying the high quality factor resonant modes results in unidirectional emission in free space. In the presence of a waveguide, evanescent coupling also becomes directional, and the output direction...
Source: http://arxiv.org/abs/1201.2352v2
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87
Sep 18, 2013
09/13
by
Harishankar Jayakumar; Ana Predojević; Tobias Huber; Thomas Kauten; Glenn S. Solomon; Gregor Weihs
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The strong confinement of semiconductor excitons in a quantum dot gives rise to atom-like behavior. The full benefit of such a structure is best observed in resonant excitation where the excited state can be deterministically populated and coherently manipulated. Due to large refractive index and device geometry it remains challenging to observe resonantly excited emission that is free from laser scattering in III/V self-assembled quantum dots. Here we exploit the biexciton binding energy to...
Source: http://arxiv.org/abs/1211.2613v1
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82
Sep 17, 2013
09/13
by
David Fattal; Kyo Inoue; Jelena Vuckovic; Charles Santori; Glenn S. Solomon; Yoshihisa Yamamoto
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We report the generation of polarization-entangled photons, using a quantum dot single photon source, linear optics and photodetectors. Two photons created independently are observed to violate Bell's inequality. The density matrix describing the polarization state of the postselected photon pairs is also reconstructed, and agrees well with a simple model predicting the quality of entanglement from the known parameters of the single photon source. Our scheme provides a method to generate no...
Source: http://arxiv.org/abs/quant-ph/0305048v1
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70
Sep 22, 2013
09/13
by
Charles Santori; David Fattal; Jelena Vuckovic; Glenn S. Solomon; Edo Waks; Yoshihisa Yamamoto
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Photon correlation measurements reveal memory effects in the optical emission of single InAs quantum dots with timescales from 10 to 800 ns. With above-band optical excitation, a long-timescale negative correlation (antibunching) is observed, while with quasi-resonant excitation, a positive correlation (blinking) is observed. A simple model based on long-lived charged states is presented that approximately explains the observed behavior, providing insight into the excitation process. Such...
Source: http://arxiv.org/abs/cond-mat/0308323v1
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7.0
Jun 30, 2018
06/18
by
Tim Thomay; Sergey V. Polyakov; Olivier Gazzano; Elizabeth Goldschmidt; Vivien Loo; Glenn S. Solomon
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eye 7
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As single-photon sources become more mature and are used more often in quantum information, communications and measurement applications, their characterization becomes more important. Single-photon-like light is often characterized by its brightness, and two quantum properties: the single-photon composition and the photon indistinguishability. While it is desirable to obtain these quantities from a single measurement, currently two or more measurements are required. Here, we simultaneously...
Topic: Quantum Physics
Source: http://arxiv.org/abs/1701.07040
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49
Sep 19, 2013
09/13
by
Matthew Pelton; Charles Santori; Jelena Vuckovic; Bingyang Zhang; Glenn S. Solomon; Jocelyn Plant; Yoshihisa Yamamoto
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We have demonstrated efficient production of triggered single photons by coupling a single semiconductor quantum dot to a three-dimensionally confined optical mode in a micropost microcavity. The efficiency of emitting single photons into a single-mode travelling wave is approximately 38%, which is nearly two orders of magnitude higher than for a quantum dot in bulk semiconductor material. At the same time, the probability of having more than one photon in a given pulse is reduced by a factor...
Source: http://arxiv.org/abs/quant-ph/0208054v1
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45
Sep 23, 2013
09/13
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Jin-Kyu Yang; Heeso Noh; Michael J. Rooks; Glenn S. Solomon; Frank Vollmer; Hui Cao
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We demonstrate lasing in GaAs photonic crystal waveguides with InAs quantum dots as gain medium. Structural disorder is present due to fabrication imperfection and causes multiple scat- tering of light and localization of light. Lasing modes with varying spatial extend are observed at random locations along the guide. Lasing frequencies are determined by the local structure and occur within a narrow frequency band which coincides with the slow light regime of the waveguide mode. The...
Source: http://arxiv.org/abs/1105.0465v1
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7.0
Jun 30, 2018
06/18
by
Sebastian Knitter; Seng Fatt Liew; Wen Xiong; Mikhael I. Guy; Glenn S. Solomon; Hui Cao
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eye 7
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We demonstrate topological defect lasers in a GaAs membrane with embedded InAs quantum dots. By introducing a disclination to a square-lattice of elliptical air holes, we obtain spatially confined optical resonances with high quality factor. Such resonances support powerflow vortices, and lase upon optical excitation of quantum dots, embedded in the structure. The spatially inhomogeneous variation of the unit cell orientation adds another dimension to the control of a lasing mode, enabling the...
Topics: Physics, Optics
Source: http://arxiv.org/abs/1412.4757
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17
Jun 27, 2018
06/18
by
Tobias Huber; Laurin Ostermann; Maximilian Prilmüller; Glenn S. Solomon; Helmut Ritsch; Gregor Weihs; Ana Predojević
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We report on the generation of time-bin entangled photon pairs from a semiconductor quantum dot via pulsed resonant biexciton generation. Based on theoretical modeling we optimized the duration of the excitation pulse to minimize the laser-induced dephasing and increase the biexciton-to-background single exciton occupation probability. This results in a high degree of entanglement with a concurrence of up to 0.78(6) and a 0.88(3) overlap with a maximally entangled state. Theoretical simulations...
Topic: Quantum Physics
Source: http://arxiv.org/abs/1506.02429
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56
Sep 22, 2013
09/13
by
Edward B. Flagg; Andreas Muller; Sergey V. Polyakov; Alex Ling; Alan Migdall; Glenn S. Solomon
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We demonstrate and characterize interference between discrete photons emitted by two separate semiconductor quantum dot states in different samples excited by a pulsed laser. Their energies are tuned into resonance using strain. The photons have a total coalescence probability of 18.1% and the coincidence rate is below the classical limit. Post-selection of coincidences within a narrow time window increases the coalescence probability to 47%. The probabilities are reduced from unity because of...
Source: http://arxiv.org/abs/1004.0153v1
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51
Sep 18, 2013
09/13
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Ana Predojevic; Miroslav Jezek; Tobias Huber; Harishankar Jayakumar; Thomas Kauten; Glenn S. Solomon; Radim Filip; Gregor Weihs
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eye 51
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The development of linear quantum computing within integrated circuits demands high quality semiconductor single photon sources. In particular it is not sufficient to just have a low multiphoton component, but also to have high efficiency. We investigate the photon statistics of the emission from a single quantum dot with a method that is able to sensitively distinguish between higher and lower quality single-photon sources. Our measurements show, for the first time, that the light emitted from...
Source: http://arxiv.org/abs/1211.2993v2
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54
Sep 23, 2013
09/13
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Sergey V. Polyakov; Andreas Muller; Edward B. Flagg; Alex Ling; Natalia Borjemscaia; Edward Van Keuren; Alan Migdall; Glenn S. Solomon
texts
eye 54
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Single photons produced by fundamentally dissimilar physical processes will in general not be indistinguishable. We show how photons produced from a quantum dot and by parametric down-conversion in a nonlinear crystal can be manipulated to be indistinguishable. The measured two-photon coalescence probability is 16%, and is limited by quantum-dot decoherence. Temporal filtering to the quantum dot coherence time and accounting for detector time response increases this to 61% while retaining 25%...
Source: http://arxiv.org/abs/1109.6254v1
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3.0
Jun 30, 2018
06/18
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Ivo Straka; Ana Predojević; Tobias Huber; Lukáš Lachman; Lorenz Butschek; Martina Miková; Michal Mičuda; Glenn S. Solomon; Gregor Weihs; Miroslav Ježek; Radim Filip
texts
eye 3
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We introduce and experimentally explore the concept of quantum non-Gaussian depth of single-photon states with a positive Wigner function. The depth measures the robustness of a single-photon state against optical losses. The directly witnessed quantum non-Gaussianity withstands significant attenuation, exhibiting a depth of 18 dB, while the nonclassicality remains unchanged. Quantum non-Gaussian depth is an experimentally approachable quantity that is much more robust than the negativity of...
Topic: Quantum Physics
Source: http://arxiv.org/abs/1403.4194
