Matthew Rakher | Hughes Research Laboratories (original) (raw)

Papers by Matthew Rakher

Single self-assembled InAs quantum dots embedded in GaAs photonic crystal (PC) defect cavities ar... more Single self-assembled InAs quantum dots embedded in GaAs photonic crystal (PC) defect cavities are a promising system for cavity quantum electrodynamics experiments. Achieving controllable coupling between the PC cavity mode and quantum dot emission is difficult, however, due to the random nucleation locations and spectral properties of individual quantum dots. We have developed a novel, all optical scheme for locating

We develop a silicon cavity optomechanical sensor for atomic force microscopy through near-field ... more We develop a silicon cavity optomechanical sensor for atomic force microscopy through near-field coupling between a nanocantilever and microdisk cavity. The device exhibits sub-fm/ p Hz displacement sensitivity, GHz bandwidth, and > 60 dB of dynamic range. Fig. 1. (a) Scanning electron microscope image of the cantilever-microdisk device, with the FEM-calculated z-component of the magnetic field for the TE1;51 mode

New Journal of Physics, 2015

We propose and investigate a hybrid optomechanical system consisting of a micro-mechanical oscill... more We propose and investigate a hybrid optomechanical system consisting of a micro-mechanical oscillator coupled to the internal states of a distant ensemble of atoms. The interaction between the systems is mediated by a light field which allows to couple the two systems in a modular way over long distances. Coupling to internal degrees of freedom of atoms opens up the possibility to employ high-frequency mechanical resonators in the MHz to GHz regime, such as optomechanical crystal structures, and to benefit from the rich toolbox of quantum control over internal atomic states. Previous schemes involving atomic motional states are rather limited in both of these aspects. We derive a full quantum model for the effective coupling including the main sources of decoherence. As an application we show that sympathetic ground-state cooling and strong coupling between the two systems is possible.

Quantum Dots, Particles, and Nanoclusters IV, 2007

Cavity quantum electrodynamic (QED) effects are studied in semiconductor microcavities embedded w... more Cavity quantum electrodynamic (QED) effects are studied in semiconductor microcavities embedded with InGaAs quantum dots. Evidence of weak coupling in the form of lifetime enhancement (the Purcell effect) and inhibition is found in both oxide-apertured micropillars and photonic crystals. In addition, high-efficiency, low-threshold lasing is observed in the photonic crystal cavities where only 2-4 quantum dots exist within the cavity mode volume and are not in general spectrally resonant. The transition to lasing in these soft turn-on devices is explored in a series of nanocavities by observing the change in photon statistics of the cavity mode with increasing pump power near the threshold.

2006 Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference, 2006

ABSTRACT We demonstrate characteristics of InAs/GaAs quantum-dot photonic-crystal lasers with hig... more ABSTRACT We demonstrate characteristics of InAs/GaAs quantum-dot photonic-crystal lasers with high spontaneous emission coupling efficiencies and soft-turn-on behaviors. Pronounced bunching signals subside with the increase of pumping, revealing the onset of lasing operations.

2007 Quantum Electronics and Laser Science Conference, 2007

A single photon source is demonstrated using a novel oxide-apertured micropillar cavity embedded ... more A single photon source is demonstrated using a novel oxide-apertured micropillar cavity embedded with InGaAs quantum dots. A bright 80 MHz count rate is enabled by the Purcell effect and charge-tuning of the quantum dots.

2005 Quantum Electronics and Laser Science Conference, 2005

ABSTRACT We present the first demonstration of Jozsa's "counterfactual computati... more ABSTRACT We present the first demonstration of Jozsa's "counterfactual computation", using an optical Grover's search algorithm. We put the algorithm in a superposition of "running" and "not-running", obtaining information even though the algorithm does not run.

Physical Review A, 2013

ABSTRACT Epitaxially grown quantum dots (QDs) are promising sources of non-classical states of li... more ABSTRACT Epitaxially grown quantum dots (QDs) are promising sources of non-classical states of light such as single photons and entangled photons. However, in order for them to be used as a resource for long-distance quantum communication, distributed quantum computation, or linear optics quantum computing, these photons must be coupled efficiently to long-lived quantum memories as part of a quantum repeater network. Here, we theoretically examine the prospects for efficient storage and retrieval of a QD-generated single photon with a 1 ns lifetime in a multi-level atomic system. We calculate using an experimentally demonstrated optical depth of 150 that the storage (total) efficiency can exceed 46% (28%) in a dense, ultracold ensemble of 87^{87}87Rb atoms. Furthermore, we find that the optimal control pulse required for storage and retrieval can be obtained using a diode laser and an electro-optic modulator rather than a mode-locked, pulsed laser source. Increasing the optical depth, for example by using Bose-condensed ensembles or an optical cavity, can increase the efficiencies to near unity. Aside from enabling a high-speed quantum network based on QDs, such an efficient optical interface between an atomic ensemble and a QD can also lead to entanglement between collective spin-wave excitations of atoms and the spin of an electron or hole confined in the QD.

CLEO: 2013, 2013

ABSTRACT Using background-free quantum frequency conversion, two spectrally separate excitonic tr... more ABSTRACT Using background-free quantum frequency conversion, two spectrally separate excitonic transitions from a single semiconductor quantum dot are converted to a single wavelength, and two-photon interference on the frequency-converted signal is demonstrated.

2005 Quantum Electronics and Laser Science Conference, 2005

We have fabricated L3-type photonic crystal microcavities with embedded InAs/GaAs quantum dots as... more We have fabricated L3-type photonic crystal microcavities with embedded InAs/GaAs quantum dots as active material. Single mode lasing has been found for devices emitting between 910-975 nm showing ultra-low lasing thresholds down to 160 nanoWatt.

Conference on Lasers and Electro-Optics 2010, 2010

ABSTRACT We investigate fiber-coupled waveguides engineered for efficient interaction with single... more ABSTRACT We investigate fiber-coupled waveguides engineered for efficient interaction with single semiconductor quantum dots, with calculated fluorescence collection 70% and 15dB transmission contrast upon resonant excitation. Characterization of passive waveguides and preliminary photoluminescence measurements are presented.

CLEO:2011 - Laser Applications to Photonic Applications, 2011

ABSTRACT We demonstrate a suspended circular grating for efficient, broadband photoluminescence s... more ABSTRACT We demonstrate a suspended circular grating for efficient, broadband photoluminescence spectroscopy of single self-assembled InAs quantum dots. Collected photon rates are 20 times greater than in bulk, and significant radiative lifetime reduction is observed.

Frontiers in Optics 2010/Laser Science XXVI, 2010

ABSTRACT Fiber-coupled waveguides are realized for broadband spectroscopy of InAs quantum dots. A... more ABSTRACT Fiber-coupled waveguides are realized for broadband spectroscopy of InAs quantum dots. Above-band and p-shell excitation of individual dots is performed, with fluorescence collection into the fiber exceeding free-space collection by one order of magnitude.

IEEE Photonics Conference 2012, 2012

Abstract—Single photon sources based on a self-assembled quantum dot in nanophotonic waveguides, ... more Abstract—Single photon sources based on a self-assembled quantum dot in nanophotonic waveguides, gratings, and cavities are interfaced with nonlinear media and electro-optic modulators to demonstrate quantum frequency conversion and amplitude modulation of single photon states. I. INTRODUCTION Single photon sources (SPSs) have many potential uses in quantum information science [1]. Important characteristics of a SPS include whether photon generation is triggered ('ondemand') or heralded, the brightness of the source into ...

Frontiers in Optics 2013, 2013

ABSTRACT We describe different experiments demonstrating quantum frequency conversion of single p... more ABSTRACT We describe different experiments demonstrating quantum frequency conversion of single photons produced by a quantum dot, and present efforts at developing new frequency converters using four-wave-mixing and cavity optomechanics in the Si3N4 platform.

Optical Techniques for Solid-State Materials Characterization, 2011

Nature nanotechnology, 2015

Sympathetic cooling with ultracold atoms and atomic ions enables ultralow temperatures in systems... more Sympathetic cooling with ultracold atoms and atomic ions enables ultralow temperatures in systems where direct laser or evaporative cooling is not possible. It has so far been limited to the cooling of other microscopic particles, with masses up to 90 times larger than that of the coolant atom. Here, we use ultracold atoms to sympathetically cool the vibrations of a Si3N4 nanomembrane, the mass of which exceeds that of the atomic ensemble by a factor of 10(10). The coupling of atomic and membrane vibrations is mediated by laser light over a macroscopic distance and is enhanced by placing the membrane in an optical cavity. We observe cooling of the membrane vibrations from room temperature to 650 ± 230 mK, exploiting the large atom-membrane cooperativity of our hybrid optomechanical system. With technical improvements, our scheme could provide ground-state cooling and quantum control of low-frequency oscillators such as nanomembranes or levitated nanoparticles, in a regime where pure...

Frontiers in Optics 2011/Laser Science XXVII, 2011

... matthew.rakher@gmail.com; Current Address: Departe-ment Physik, Universität Basel, Klingelber... more ... matthew.rakher@gmail.com; Current Address: Departe-ment Physik, Universität Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland [1] HJ Kimble, Nature (London) 453, 1023 (2008). ... Lett. 103, 087406 (2009). [15] GS Vasilev, D. Ljunggren, and A. Kuhn, New J. Phys. ...

LEOS 2008 - 21st Annual Meeting of the IEEE Lasers and Electro-Optics Society, 2008

Recent years have shown tremendous progress in the fabrication of single photon sources (SPS) bas... more Recent years have shown tremendous progress in the fabrication of single photon sources (SPS) based on quantum dots (QDs) embedded in semiconductor micro and nanocavities which are of interest for applications in quantum information science. Here we will review our recent work on high-frequency single photon sources operating at single photon emission rates above 100MHz. To effectively harvest the radiative recombination of QD excitons and to overcome the total internal reflection losses of high index semiconductor materials the emission can be coupled into a cavity mode.

Frontiers in Optics 2011/Laser Science XXVII, 2011

ABSTRACT An optical lattice formed by reflection from a SiN$_x$ membrane creates a bi-directional... more ABSTRACT An optical lattice formed by reflection from a SiN$_x$ membrane creates a bi-directional coupling of atomic and membrane motion. Experimental demonstrations of both direct-action and backaction in this system are reported.

Single self-assembled InAs quantum dots embedded in GaAs photonic crystal (PC) defect cavities ar... more Single self-assembled InAs quantum dots embedded in GaAs photonic crystal (PC) defect cavities are a promising system for cavity quantum electrodynamics experiments. Achieving controllable coupling between the PC cavity mode and quantum dot emission is difficult, however, due to the random nucleation locations and spectral properties of individual quantum dots. We have developed a novel, all optical scheme for locating

We develop a silicon cavity optomechanical sensor for atomic force microscopy through near-field ... more We develop a silicon cavity optomechanical sensor for atomic force microscopy through near-field coupling between a nanocantilever and microdisk cavity. The device exhibits sub-fm/ p Hz displacement sensitivity, GHz bandwidth, and > 60 dB of dynamic range. Fig. 1. (a) Scanning electron microscope image of the cantilever-microdisk device, with the FEM-calculated z-component of the magnetic field for the TE1;51 mode

New Journal of Physics, 2015

We propose and investigate a hybrid optomechanical system consisting of a micro-mechanical oscill... more We propose and investigate a hybrid optomechanical system consisting of a micro-mechanical oscillator coupled to the internal states of a distant ensemble of atoms. The interaction between the systems is mediated by a light field which allows to couple the two systems in a modular way over long distances. Coupling to internal degrees of freedom of atoms opens up the possibility to employ high-frequency mechanical resonators in the MHz to GHz regime, such as optomechanical crystal structures, and to benefit from the rich toolbox of quantum control over internal atomic states. Previous schemes involving atomic motional states are rather limited in both of these aspects. We derive a full quantum model for the effective coupling including the main sources of decoherence. As an application we show that sympathetic ground-state cooling and strong coupling between the two systems is possible.

Quantum Dots, Particles, and Nanoclusters IV, 2007

Cavity quantum electrodynamic (QED) effects are studied in semiconductor microcavities embedded w... more Cavity quantum electrodynamic (QED) effects are studied in semiconductor microcavities embedded with InGaAs quantum dots. Evidence of weak coupling in the form of lifetime enhancement (the Purcell effect) and inhibition is found in both oxide-apertured micropillars and photonic crystals. In addition, high-efficiency, low-threshold lasing is observed in the photonic crystal cavities where only 2-4 quantum dots exist within the cavity mode volume and are not in general spectrally resonant. The transition to lasing in these soft turn-on devices is explored in a series of nanocavities by observing the change in photon statistics of the cavity mode with increasing pump power near the threshold.

2006 Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference, 2006

ABSTRACT We demonstrate characteristics of InAs/GaAs quantum-dot photonic-crystal lasers with hig... more ABSTRACT We demonstrate characteristics of InAs/GaAs quantum-dot photonic-crystal lasers with high spontaneous emission coupling efficiencies and soft-turn-on behaviors. Pronounced bunching signals subside with the increase of pumping, revealing the onset of lasing operations.

2007 Quantum Electronics and Laser Science Conference, 2007

A single photon source is demonstrated using a novel oxide-apertured micropillar cavity embedded ... more A single photon source is demonstrated using a novel oxide-apertured micropillar cavity embedded with InGaAs quantum dots. A bright 80 MHz count rate is enabled by the Purcell effect and charge-tuning of the quantum dots.

2005 Quantum Electronics and Laser Science Conference, 2005

ABSTRACT We present the first demonstration of Jozsa's "counterfactual computati... more ABSTRACT We present the first demonstration of Jozsa's "counterfactual computation", using an optical Grover's search algorithm. We put the algorithm in a superposition of "running" and "not-running", obtaining information even though the algorithm does not run.

Physical Review A, 2013

ABSTRACT Epitaxially grown quantum dots (QDs) are promising sources of non-classical states of li... more ABSTRACT Epitaxially grown quantum dots (QDs) are promising sources of non-classical states of light such as single photons and entangled photons. However, in order for them to be used as a resource for long-distance quantum communication, distributed quantum computation, or linear optics quantum computing, these photons must be coupled efficiently to long-lived quantum memories as part of a quantum repeater network. Here, we theoretically examine the prospects for efficient storage and retrieval of a QD-generated single photon with a 1 ns lifetime in a multi-level atomic system. We calculate using an experimentally demonstrated optical depth of 150 that the storage (total) efficiency can exceed 46% (28%) in a dense, ultracold ensemble of 87^{87}87Rb atoms. Furthermore, we find that the optimal control pulse required for storage and retrieval can be obtained using a diode laser and an electro-optic modulator rather than a mode-locked, pulsed laser source. Increasing the optical depth, for example by using Bose-condensed ensembles or an optical cavity, can increase the efficiencies to near unity. Aside from enabling a high-speed quantum network based on QDs, such an efficient optical interface between an atomic ensemble and a QD can also lead to entanglement between collective spin-wave excitations of atoms and the spin of an electron or hole confined in the QD.

CLEO: 2013, 2013

ABSTRACT Using background-free quantum frequency conversion, two spectrally separate excitonic tr... more ABSTRACT Using background-free quantum frequency conversion, two spectrally separate excitonic transitions from a single semiconductor quantum dot are converted to a single wavelength, and two-photon interference on the frequency-converted signal is demonstrated.

2005 Quantum Electronics and Laser Science Conference, 2005

We have fabricated L3-type photonic crystal microcavities with embedded InAs/GaAs quantum dots as... more We have fabricated L3-type photonic crystal microcavities with embedded InAs/GaAs quantum dots as active material. Single mode lasing has been found for devices emitting between 910-975 nm showing ultra-low lasing thresholds down to 160 nanoWatt.

Conference on Lasers and Electro-Optics 2010, 2010

ABSTRACT We investigate fiber-coupled waveguides engineered for efficient interaction with single... more ABSTRACT We investigate fiber-coupled waveguides engineered for efficient interaction with single semiconductor quantum dots, with calculated fluorescence collection 70% and 15dB transmission contrast upon resonant excitation. Characterization of passive waveguides and preliminary photoluminescence measurements are presented.

CLEO:2011 - Laser Applications to Photonic Applications, 2011

ABSTRACT We demonstrate a suspended circular grating for efficient, broadband photoluminescence s... more ABSTRACT We demonstrate a suspended circular grating for efficient, broadband photoluminescence spectroscopy of single self-assembled InAs quantum dots. Collected photon rates are 20 times greater than in bulk, and significant radiative lifetime reduction is observed.

Frontiers in Optics 2010/Laser Science XXVI, 2010

ABSTRACT Fiber-coupled waveguides are realized for broadband spectroscopy of InAs quantum dots. A... more ABSTRACT Fiber-coupled waveguides are realized for broadband spectroscopy of InAs quantum dots. Above-band and p-shell excitation of individual dots is performed, with fluorescence collection into the fiber exceeding free-space collection by one order of magnitude.

IEEE Photonics Conference 2012, 2012

Abstract—Single photon sources based on a self-assembled quantum dot in nanophotonic waveguides, ... more Abstract—Single photon sources based on a self-assembled quantum dot in nanophotonic waveguides, gratings, and cavities are interfaced with nonlinear media and electro-optic modulators to demonstrate quantum frequency conversion and amplitude modulation of single photon states. I. INTRODUCTION Single photon sources (SPSs) have many potential uses in quantum information science [1]. Important characteristics of a SPS include whether photon generation is triggered ('ondemand') or heralded, the brightness of the source into ...

Frontiers in Optics 2013, 2013

ABSTRACT We describe different experiments demonstrating quantum frequency conversion of single p... more ABSTRACT We describe different experiments demonstrating quantum frequency conversion of single photons produced by a quantum dot, and present efforts at developing new frequency converters using four-wave-mixing and cavity optomechanics in the Si3N4 platform.

Optical Techniques for Solid-State Materials Characterization, 2011

Nature nanotechnology, 2015

Sympathetic cooling with ultracold atoms and atomic ions enables ultralow temperatures in systems... more Sympathetic cooling with ultracold atoms and atomic ions enables ultralow temperatures in systems where direct laser or evaporative cooling is not possible. It has so far been limited to the cooling of other microscopic particles, with masses up to 90 times larger than that of the coolant atom. Here, we use ultracold atoms to sympathetically cool the vibrations of a Si3N4 nanomembrane, the mass of which exceeds that of the atomic ensemble by a factor of 10(10). The coupling of atomic and membrane vibrations is mediated by laser light over a macroscopic distance and is enhanced by placing the membrane in an optical cavity. We observe cooling of the membrane vibrations from room temperature to 650 ± 230 mK, exploiting the large atom-membrane cooperativity of our hybrid optomechanical system. With technical improvements, our scheme could provide ground-state cooling and quantum control of low-frequency oscillators such as nanomembranes or levitated nanoparticles, in a regime where pure...

Frontiers in Optics 2011/Laser Science XXVII, 2011

... matthew.rakher@gmail.com; Current Address: Departe-ment Physik, Universität Basel, Klingelber... more ... matthew.rakher@gmail.com; Current Address: Departe-ment Physik, Universität Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland [1] HJ Kimble, Nature (London) 453, 1023 (2008). ... Lett. 103, 087406 (2009). [15] GS Vasilev, D. Ljunggren, and A. Kuhn, New J. Phys. ...

LEOS 2008 - 21st Annual Meeting of the IEEE Lasers and Electro-Optics Society, 2008

Recent years have shown tremendous progress in the fabrication of single photon sources (SPS) bas... more Recent years have shown tremendous progress in the fabrication of single photon sources (SPS) based on quantum dots (QDs) embedded in semiconductor micro and nanocavities which are of interest for applications in quantum information science. Here we will review our recent work on high-frequency single photon sources operating at single photon emission rates above 100MHz. To effectively harvest the radiative recombination of QD excitons and to overcome the total internal reflection losses of high index semiconductor materials the emission can be coupled into a cavity mode.

Frontiers in Optics 2011/Laser Science XXVII, 2011

ABSTRACT An optical lattice formed by reflection from a SiN$_x$ membrane creates a bi-directional... more ABSTRACT An optical lattice formed by reflection from a SiN$_x$ membrane creates a bi-directional coupling of atomic and membrane motion. Experimental demonstrations of both direct-action and backaction in this system are reported.