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Sven Hofling - One of the best experts on this subject based on the ideXlab platform.

  • observation of intensity squeezing in Resonance Fluorescence from a solid state device
    Physical Review Letters, 2020
    Co-Authors: Hui Wang, Si Chen, Jian Qin, Mingcheng Chen, Xiang You, Xing Ding, Yongheng Huo, Christian Schneider, Sven Hofling, Marlan O Scully
    Abstract:

    Intensity squeezing-i.e., photon number fluctuations below the shot-noise limit-is a fundamental aspect of quantum optics and has wide applications in quantum metrology. It was predicted in 1979 that intensity squeezing could be observed in Resonance Fluorescence from a two-level quantum system. However, its experimental observation in solid states was hindered by inefficiencies in generating, collecting, and detecting Resonance Fluorescence. Here, we report the intensity squeezing in a single-mode fiber-coupled Resonance Fluorescence single-photon source based on a quantum dot-micropillar system. We detect pulsed single-photon streams with 22.6% system efficiency, which show sub-shot-noise intensity fluctuation with an intensity squeezing of 0.59 dB. We estimate a corrected squeezing of 3.29 dB at the first lens. The observed intensity squeezing provides the last piece of the fundamental picture of Resonance Fluorescence, which can be used as a new standard for optical radiation and in scalable quantum metrology with indistinguishable single photons.

  • near unity indistinguishability single photon source for large scale integrated quantum optics
    Physical Review Letters, 2019
    Co-Authors: ł Dusanowski, Christian Schneider, Sven Hofling, Soonhong Kwon
    Abstract:

    Integrated single photon sources are key building blocks for realizing scalable devices for quantum information processing. For such applications highly coherent and indistinguishable single photons on a chip are required. Here we report on a triggered Resonance Fluorescence single photon source based on In(Ga)As/GaAs quantum dots coupled to single- and multimode ridge waveguides. We demonstrate the generation of highly linearly polarized Resonance Fluorescence photons with 99.1% (96.0%) single photon purity and 97.5% (95.0%) indistinguishability in case of multimode (single mode) waveguide devices fulfilling the strict requirements imposed by multi-interferometric quantum optics applications. Our integrated triggered single photon source can be readily scaled up, promising a realistic pathway for on-chip linear optical quantum simulation, quantum computation, and quantum networks.

  • highly indistinguishable on demand Resonance Fluorescence photons from a deterministic quantum dot micropillar device with 74 extraction efficiency
    Optics Express, 2016
    Co-Authors: Sebastian Unsleber, Christian Schneider, Jian-wei Pan, Martin Kamp, Stefan Gerhardt, Sebastian Maier, Niels Gregersen, Sven Hofling
    Abstract:

    The implementation and engineering of bright and coherent solid state quantum light sources is key for the realization of both on chip and remote quantum networks. Despite tremendous efforts for more than 15 years, the combination of these two key prerequisites in a single, potentially scalable device is a major challenge. Here, we report on the observation of bright single photon emission generated via pulsed, Resonance Fluorescence conditions from a single quantum dot (QD) deterministically centered in a micropillar cavity device via cryogenic optical lithography. The brightness of the QD Fluorescence is greatly enhanced on Resonance with the fundamental mode of the pillar, leading to an overall device efficiency of η = (74 ± 4) % for a single photon emission as pure as g(2)(0) = 0.0092 ± 0.0004. The combination of large Purcell enhancement and resonant pumping conditions allows us to observe a two-photon wave packet overlap up to ν = (88 ± 3) %.

  • highly indistinguishable on demand Resonance Fluorescence photons from a deterministic quantum dot micropillar device with 75 extraction efficiency
    arXiv: Quantum Physics, 2015
    Co-Authors: Sebastian Unsleber, Christian Schneider, Jian-wei Pan, Martin Kamp, Stefan Gerhardt, Sebastian Maier, Sven Hofling
    Abstract:

    The implementation and engineering of bright and coherent solid state quantum light sources is key for the realization of both on chip and remote quantum networks. Despite tremendous efforts for more than 15 years, the combination of these two key prerequisites in a single, potentially scalable device is a major challenge. Here, we report on the observation of bright and coherent single photon emission generated via pulsed, Resonance Fluorescence conditions from a single quantum dot (QD) deterministically centered in a micropillar cavity device via cryogenic optical lithography. The brightness of the QD Fluorescence is greatly enhanced on Resonance with the fundamental mode of the pillar, leading to an overall device efficiency of $\eta=(74\pm4)~\%$ for a single photon emission as pure as $g^{(2)}(0)=0.0092\pm0.0004$. The combination of large Purcell enhancement and resonant pumping conditions allows us to observe a two-photon wave packet overlap up to $\nu=(88\pm3)~\%$

  • on demand semiconductor single photon source with near unity indistinguishability
    Nature Nanotechnology, 2013
    Co-Authors: Yujia Wei, Christian Schneider, Sven Hofling, Mete Atature, Martin Kamp, Jian-wei Pan
    Abstract:

    Pulse-excited Resonance-Fluorescence single-photons are generated on demand from a single quantum dot embedded in a microcavity under s-shell excitation with an ultrafast laser source.

Mete Atature - One of the best experts on this subject based on the ideXlab platform.

  • on demand semiconductor single photon source with near unity indistinguishability
    Nature Nanotechnology, 2013
    Co-Authors: Yujia Wei, Christian Schneider, Sven Hofling, Mete Atature, Martin Kamp, Jian-wei Pan
    Abstract:

    Pulse-excited Resonance-Fluorescence single-photons are generated on demand from a single quantum dot embedded in a microcavity under s-shell excitation with an ultrafast laser source.

  • on demand semiconductor single photon source with near unity indistinguishability
    International Photonics and Optoelectronics Meetings (2012) paper IF1A.3, 2012
    Co-Authors: Yujia Wei, Christian Schneider, Sven Hofling, Mete Atature, Martin Kamp, Jian-wei Pan
    Abstract:

    We generate pulsed Resonance Fluorescence single photons on demand from a single, microcavity-embedded quantum dot with less than 0.3% background contributions and a Hong-Ou-Mandel interference visibility of 0.970(19). Two single photons are further used to implement a high-fidelity quantum controlled-NOT gate.

  • observation of spin dependent quantum jumps via quantum dot Resonance Fluorescence
    Nature, 2010
    Co-Authors: A N Vamivakas, Y Zhao, Clemens Matthiesen, S Falt, Antonio Badolato, Mete Atature
    Abstract:

    A promising approach to realizing a practical qubit scheme for quantum computation involves the optical control of single electron spins in semiconductor quantum dots. Rapid progress towards the reliable preparation and manipulation of the quantum states of such spins has been achieved in recent years. The final challenge is to carry out 'single shot' measurements of the electron spin without interfering with it. Vamivakas et al. have now developed a technique that enables such a measurement through coupling of one quantum dot to another. This quantum dot 'molecule', unlike its single quantum dot counterpart, allows separate and independent optical transitions for state preparation, manipulation and measurement, avoiding the dilemma of relying on the same transition to address the spin state of an electron. As a result, the authors show, it is possible to observe spin quantum jumps in real time. A promising approach to realizing a practical quantum bit scheme is the optical control of single electron spins in quantum dots. The reliable preparation and manipulation of the quantum states of such spins have been demonstrated recently. The final challenge is to carry out single-shot measurements of the electron spin without interfering with it. A technique has now been developed that enables such measurement, by coupling one quantum dot to another to produce a quantum dot molecule. Reliable preparation, manipulation and measurement protocols are necessary to exploit a physical system as a quantum bit1. Spins in optically active quantum dots offer one potential realization2,3 and recent demonstrations have shown high-fidelity preparation4,5 and ultrafast coherent manipulation6,7,8. The final challenge—that is, single-shot measurement of the electron spin—has proved to be the most difficult of the three and so far only time-averaged optical measurements have been reported9,10,11,12. The main obstacle to optical spin readout in single quantum dots is that the same laser that probes the spin state also flips the spin being measured. Here, by using a gate-controlled quantum dot molecule13,14,15, we present the ability to measure the spin state of a single electron in real time via the intermittency of quantum dot Resonance Fluorescence12,16. The quantum dot molecule, unlike its single quantum dot counterpart, allows separate and independent optical transitions for state preparation, manipulation and measurement, avoiding the dilemma of relying on the same transition to address the spin state of an electron.

  • spin resolved quantum dot Resonance Fluorescence
    Nature Physics, 2009
    Co-Authors: Nick A Vamivakas, Y Zhao, Mete Atature
    Abstract:

    Two experiments observe the so-called ‘Mollow triplet’ in the emission spectrum of a quantum dot—originating from resonantly driving a dot transition—and demonstrate the potential of these systems to act as single-photon sources and as a readout modality for electron-spin states. Confined spins in self-assembled semiconductor quantum dots promise to serve both as probes for studying mesoscopic physics in the solid state and as stationary qubits for quantum-information science1,2,3,4,5,6,7. Moreover, the excitations of self-assembled quantum dots can interact with near-infrared photons, providing an interface between stationary and ‘flying’ qubits. Here, we report the observation of spin-selective photon emission from a resonantly driven quantum-dot transition. The Mollow triplet8 in the scattered photon spectrum—the hallmark of Resonance Fluorescence when an optical transition is driven resonantly—is presented as a natural way to spectrally isolate the photons of interest from the original driving field. We also demonstrate that the relative frequencies of the two spin-tagged photon states can be tuned independent of an applied magnetic field through the spin-selective dynamic Stark effect, induced by the same driving laser. This demonstration should be a step towards the realization of challenging tasks such as electron-spin readout, heralded single-photon generation for linear-optics quantum computing and spin–photon entanglement.

Christian Schneider - One of the best experts on this subject based on the ideXlab platform.

  • observation of intensity squeezing in Resonance Fluorescence from a solid state device
    Physical Review Letters, 2020
    Co-Authors: Hui Wang, Si Chen, Jian Qin, Mingcheng Chen, Xiang You, Xing Ding, Yongheng Huo, Christian Schneider, Sven Hofling, Marlan O Scully
    Abstract:

    Intensity squeezing-i.e., photon number fluctuations below the shot-noise limit-is a fundamental aspect of quantum optics and has wide applications in quantum metrology. It was predicted in 1979 that intensity squeezing could be observed in Resonance Fluorescence from a two-level quantum system. However, its experimental observation in solid states was hindered by inefficiencies in generating, collecting, and detecting Resonance Fluorescence. Here, we report the intensity squeezing in a single-mode fiber-coupled Resonance Fluorescence single-photon source based on a quantum dot-micropillar system. We detect pulsed single-photon streams with 22.6% system efficiency, which show sub-shot-noise intensity fluctuation with an intensity squeezing of 0.59 dB. We estimate a corrected squeezing of 3.29 dB at the first lens. The observed intensity squeezing provides the last piece of the fundamental picture of Resonance Fluorescence, which can be used as a new standard for optical radiation and in scalable quantum metrology with indistinguishable single photons.

  • near unity indistinguishability single photon source for large scale integrated quantum optics
    Physical Review Letters, 2019
    Co-Authors: ł Dusanowski, Christian Schneider, Sven Hofling, Soonhong Kwon
    Abstract:

    Integrated single photon sources are key building blocks for realizing scalable devices for quantum information processing. For such applications highly coherent and indistinguishable single photons on a chip are required. Here we report on a triggered Resonance Fluorescence single photon source based on In(Ga)As/GaAs quantum dots coupled to single- and multimode ridge waveguides. We demonstrate the generation of highly linearly polarized Resonance Fluorescence photons with 99.1% (96.0%) single photon purity and 97.5% (95.0%) indistinguishability in case of multimode (single mode) waveguide devices fulfilling the strict requirements imposed by multi-interferometric quantum optics applications. Our integrated triggered single photon source can be readily scaled up, promising a realistic pathway for on-chip linear optical quantum simulation, quantum computation, and quantum networks.

  • highly indistinguishable on demand Resonance Fluorescence photons from a deterministic quantum dot micropillar device with 74 extraction efficiency
    Optics Express, 2016
    Co-Authors: Sebastian Unsleber, Christian Schneider, Jian-wei Pan, Martin Kamp, Stefan Gerhardt, Sebastian Maier, Niels Gregersen, Sven Hofling
    Abstract:

    The implementation and engineering of bright and coherent solid state quantum light sources is key for the realization of both on chip and remote quantum networks. Despite tremendous efforts for more than 15 years, the combination of these two key prerequisites in a single, potentially scalable device is a major challenge. Here, we report on the observation of bright single photon emission generated via pulsed, Resonance Fluorescence conditions from a single quantum dot (QD) deterministically centered in a micropillar cavity device via cryogenic optical lithography. The brightness of the QD Fluorescence is greatly enhanced on Resonance with the fundamental mode of the pillar, leading to an overall device efficiency of η = (74 ± 4) % for a single photon emission as pure as g(2)(0) = 0.0092 ± 0.0004. The combination of large Purcell enhancement and resonant pumping conditions allows us to observe a two-photon wave packet overlap up to ν = (88 ± 3) %.

  • highly indistinguishable on demand Resonance Fluorescence photons from a deterministic quantum dot micropillar device with 75 extraction efficiency
    arXiv: Quantum Physics, 2015
    Co-Authors: Sebastian Unsleber, Christian Schneider, Jian-wei Pan, Martin Kamp, Stefan Gerhardt, Sebastian Maier, Sven Hofling
    Abstract:

    The implementation and engineering of bright and coherent solid state quantum light sources is key for the realization of both on chip and remote quantum networks. Despite tremendous efforts for more than 15 years, the combination of these two key prerequisites in a single, potentially scalable device is a major challenge. Here, we report on the observation of bright and coherent single photon emission generated via pulsed, Resonance Fluorescence conditions from a single quantum dot (QD) deterministically centered in a micropillar cavity device via cryogenic optical lithography. The brightness of the QD Fluorescence is greatly enhanced on Resonance with the fundamental mode of the pillar, leading to an overall device efficiency of $\eta=(74\pm4)~\%$ for a single photon emission as pure as $g^{(2)}(0)=0.0092\pm0.0004$. The combination of large Purcell enhancement and resonant pumping conditions allows us to observe a two-photon wave packet overlap up to $\nu=(88\pm3)~\%$

  • on demand semiconductor single photon source with near unity indistinguishability
    Nature Nanotechnology, 2013
    Co-Authors: Yujia Wei, Christian Schneider, Sven Hofling, Mete Atature, Martin Kamp, Jian-wei Pan
    Abstract:

    Pulse-excited Resonance-Fluorescence single-photons are generated on demand from a single quantum dot embedded in a microcavity under s-shell excitation with an ultrafast laser source.

Jian-wei Pan - One of the best experts on this subject based on the ideXlab platform.

Richard J. Warburton - One of the best experts on this subject based on the ideXlab platform.

  • charge noise and spin noise in a semiconductor quantum device
    Nature Physics, 2013
    Co-Authors: Andreas V. Kuhlmann, Julien Houel, Arne Ludwig, Lukas Greuter, D Reuter, A D Wieck, M Poggio, Richard J. Warburton
    Abstract:

    Charge noise and spin noise lead to decoherence of the state of a quantum dot. A fast spectroscopic technique based on Resonance Fluorescence can distinguish between these two deleterious effects, enabling a better understanding of how to minimize their influence.

  • charge noise and spin noise in a semiconductor quantum device
    Nature Physics, 2013
    Co-Authors: Andreas V. Kuhlmann, Julien Houel, Arne Ludwig, Lukas Greuter, D Reuter, A D Wieck, M Poggio, Richard J. Warburton
    Abstract:

    Improving the quantum coherence of solid-state systems that mimic two-level atoms, for instance spin qubits or single-photon emitters using semiconductor quantum dots, involves dealing with the noise inherent to the device. Charge noise results in a fluctuating electric field, spin noise in a fluctuating magnetic field at the location of the qubit, and both can lead to dephasing and decoherence of optical and spin states. We investigate noise in an ultrapure semiconductor device using a minimally invasive, ultrasensitive local probe: Resonance Fluorescence from a single quantum dot. We distinguish between charge noise and spin noise through a crucial difference in their optical signatures. Noise spectra for both electric and magnetic fields are derived from 0.1 Hz to 100 kHz. The charge noise dominates at low frequencies, spin noise at high frequencies. The noise falls rapidly with increasing frequency, allowing us to demonstrate transform-limited quantum-dot optical linewidths by operating the device above 50 kHz. Charge noise and spin noise lead to decoherence of the state of a quantum dot. A fast spectroscopic technique based on Resonance Fluorescence can distinguish between these two deleterious effects, enabling a better understanding of how to minimize their influence.

  • a dark field microscope for background free detection of Resonance Fluorescence from single semiconductor quantum dots operating in a set and forget mode
    arXiv: Mesoscale and Nanoscale Physics, 2013
    Co-Authors: Andreas V. Kuhlmann, Julien Houel, Daniel Brunner, Arne Ludwig, Dirk Reuter, Andreas D. Wieck, Richard J. Warburton
    Abstract:

    Optically active quantum dots, for instance self-assembled InGaAs quantum dots, are potentially excellent single photon sources. The fidelity of the single photons is much improved using resonant rather than non-resonant excitation. With resonant excitation, the challenge is to distinguish between Resonance Fluorescence and scattered laser light. We have met this challenge by creating a polarization-based dark-field microscope to measure the Resonance Fluorescence from a single quantum dot at low temperature. We achieve a suppression of the scattered laser exceeding a factor of 10^7 and background-free detection of Resonance Fluorescence. The same optical setup operates over the entire quantum dot emission range 920-980 nm and also in high magnetic fields. The major development is the outstanding long-term stability: once the dark-field point has been established, the microscope operates for days without alignment. The mechanical and optical design of the microscope is presented, as well as exemplary Resonance Fluorescence spectroscopy results on individual quantum dots to underline the microscope's excellent performance.

  • A dark-field microscope for background-free detection of Resonance Fluorescence from single semiconductor quantum dots operating in a set-and-forget mode
    The Review of scientific instruments, 2013
    Co-Authors: Andreas V. Kuhlmann, Julien Houel, Daniel Brunner, Arne Ludwig, Dirk Reuter, Andreas D. Wieck, Richard J. Warburton
    Abstract:

    Optically active quantum dots, for instance self-assembled InGaAs quantum dots, are potentially excellent single photon sources. The fidelity of the single photons is much improved using resonant rather than non-resonant excitation. With resonant excitation, the challenge is to distinguish between Resonance Fluorescence and scattered laser light. We have met this challenge by creating a polarization-based dark-field microscope to measure the Resonance Fluorescence from a single quantum dot at low temperature. We achieve a suppression of the scattered laser exceeding a factor of 107 and background-free detection of Resonance Fluorescence. The same optical setup operates over the entire quantum dot emission range (920–980 nm) and also in high magnetic fields. The major development is the outstanding long-term stability: once the dark-field point has been established, the microscope operates for days without alignment. The mechanical and optical designs of the microscope are presented, as well as exemplary Resonance Fluorescence spectroscopy results on individual quantum dots to underline the microscope's excellent performance.