Results for "Jonathan P. Dowling"

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Quantum Optical Metrology -- The Lowdown on High-N00N StatesApr 01 2009Quantum states of light, such as squeezed states or entangled states, can be used to make measurements (metrology), produce images, and sense objects with a precision that far exceeds what is possible classically, and also exceeds what was once thought ... More
Dipole Emission In Finite Photonic Band-Gap Structures: an Exactly Solvable One-Dimensional ModelJun 04 1999I consider an exact model of atomic spontaneous dipole emission and classical dipole radiation in a finite photonic band-gap structure. The full 3D or 2D problem is reduced to a finite 1D model, and then this is solved for analytically using algebraic ... More
A Lorentz-invariant look at quantum clock synchronization protocols based on distributed entanglementOct 27 2000Recent work has raised the possibility that quantum information theory techniques can be used to synchronize atomic clocks nonlocally. One of the proposed algorithms for quantum clock synchronization (QCS) requires distribution of entangled pure singlets ... More
Heisenberg limited measurements with superconducting circuitsDec 17 2005Apr 17 2006We describe an assembly of N superconducting qubits contained in a single-mode cavity. In the dispersive regime, the correlation between the cavity field and each qubit results in an effective interaction between qubits that can be used to dynamically ... More
Generation of maximally entangled charge-qubit arrays via a cavity modeAug 08 2005We describe an assembly of N Cooper-pair boxes (CPB) contained in a single mode cavity. In the dispersive regime, the correlation between the cavity field and each Cooper-pair box results in an effective interaction between CPBs that can be used to dynamically ... More
Concatenated beam splitters, optical feed-forward and the nonlinear sign gateJun 26 2006We consider a nonlinear sign gate implemented using a sequence of two beam splitters, and consider the use of further sequences of beam splitters to implement feed-forward so as to correct an error resulting from the first beam splitter. We obtain similar ... More
A Method for Generating All Uniform $π$-Pulse Sequences Used in Deterministic Dynamical DecouplingJul 27 2015Dynamical decoupling has been actively investigated since Viola first suggested using a pulse sequence to protect a qubit from decoherence. Since then, many schemes of dynamical decoupling have been proposed to achieve high-order suppression, both analytically ... More
Quantum Computation--The Ultimate FrontierFeb 07 2002The discovery of an algorithm for factoring which runs in polynomial time on a quantum computer has given rise to a concerted effort to understand the principles, advantages, and limitations of quantum computing. At the same time, many different quantum ... More
Generation of Large Number-Path Entanglement Using Linear Optics and Feed-ForwardApr 05 2007We show how an idealised measurement procedure can condense photons from two modes into one, and how, by feeding forward the results of the measurement, it is possible to generate efficiently superpositions of components for which only one mode is populated, ... More
Quantum Hall effect with small numbers of vortices in Bose-Einstein condensatesJul 08 2015When vortices are displaced in Bose-Einstein condensates (BEC), the Magnus force gives the system a momentum transverse in the direction to the displacement. We show that Bose-Einstein condensates (BEC) in long channels with vortices exhibit a quantization ... More
Quantum optical technologies for metrology, sensing and imagingDec 24 2014Feb 27 2015Over the past 20 years, bright sources of entangled photons have led to a renaissance in quantum optical interferometry. Optical interferometry has been used to test the foundations of quantum mechanics and implement some of the novel ideas associated ... More
Strong violations of Bell-type inequalities for Werner-like statesAug 15 2007Sep 12 2008We investigate the violation of Bell-type inequalities for two-qubit Werner-like states parametrized by the positive parameter 0<p<1. We use an unbalanced homodyne detection scheme to obtain the quantum mechanical probabilities. A violation of the Bell-Wigner ... More
Thermal emissivity for finite three-dimensional photonic band gap crystalsDec 06 2002We discuss the results of computer model for the thermal emissivity of a three-dimensional photonic band gap (PBG) crystal, specifically an inverted opal structure. The thermal emittance for a range of frequencies and angles is calculated.
Quantum Technology: The Second Quantum RevolutionJun 13 2002We are currently in the midst of a second quantum revolution. The first quantum revolution gave us new rules that govern physical reality. The second quantum revolution will take these rules and use them to develop new technologies. In this review we ... More
Factoring integers with Young's N-slit interferometerOct 24 2008We show that a Young's N slit interferometer can be used to factor the integer N. The device could factor four- or five-digit numbers in a practical fashion. This work shows how number theory may arise in physical problems, and may provide some insight ... More
Final Report on ECCS/NSF Workshop on Quantum, Molecular and High Performance Modeling and Simulation for Devices and Systems (QMHP)Sep 20 2007Oct 26 2007The National Science Foundation has identified a new thrust area in Quantum, Molecular and High Performance Modeling and Simulation for Devices and Systems (QMHP) in its core program. The main purpose of this thrust area is to capture scientific opportunities ... More
Quantum Imaging and MetrologyJun 17 2003The manipulation of quantum entanglement has found enormous potential for improving performances of devices such as gyroscopes, clocks, and even computers. Similar improvements have been demonstrated for lithography and microscopy. We present an overview ... More
Robust quantum network architectures and topologies for entanglement distributionSep 21 2017Feb 01 2018Entanglement distribution is a prerequisite for several important quantum information processing and computing tasks, such as quantum teleportation, quantum key distribution, and distributed quantum computing. In this work, we focus on two-dimensional ... More
Probability, unitarity, and realism in generally covariant quantum informationAug 27 2007Feb 13 2008The formalism of covariant quantum theory, introduced by Reisenberger and Rovelli, casts the description of quantum states and evolution into a framework compatable with the principles of general relativity. The leap to this covariant formalism, however, ... More
Single-photon orbital angular momentum qudit states in fiber - Limits to Dephasing correction via dynamical decouplingOct 02 2015We analytically derive a decoherence model for orbital angular momentum states of a photon in a multimode optical fiber and show that rate of decoherence scales exponentially with $l^2$, where $l$ is the azimuthal mode order.~We also show numerically ... More
Quantum Computing, Metrology, and ImagingJun 17 2005Information science is entering into a new era in which certain subtleties of quantum mechanics enables large enhancements in computational efficiency and communication security. Naturally, precise control of quantum systems required for the implementation ... More
A Bootstrapping Approach for Generating Maximally Path-Entangled Photon StatesDec 22 2006Mar 18 2008We propose a bootstrapping approach to generation of maximally path-entangled states of photons, so called ``NOON states''. Strong atom-light interaction of cavity QED can be employed to generate NOON states with about 100 photons; which can then be used ... More
Information and measurement in generally covariant quantum theoryJan 28 2007Jan 18 2008Due to the absence of an external, classical time variable, the probabilistic predictions of covariant quantum theory are ambiguous when multiple measurements are considered. Here, we introduce an information theoretic framework to the covariant formalism, ... More
Popper's Thought Experiment ReinvestigatedFeb 11 2011Jan 31 2012Popper's original thought experiment probed some fundamental and subtle rules of quantum mechanics. Two experiments have directly and indirectly tested Popper's hypothesis, but they seem to give contrasting results. The equations governing these two experiments ... More
Local and Global Distinguishability in Quantum InterferometryJul 14 2006Dec 20 2006A statistical distinguishability based on relative entropy characterises the fitness of quantum states for phase estimation. This criterion is employed in the context of a Mach-Zehnder interferometer and used to interpolate between two regimes, of local ... More
The Vortex Phase Qubit: Generating Arbitrary, Counter-Rotating, Coherent Superpositions in Bose-Einstein Condensates via Optical Angular Momentum BeamsApr 17 2005We propose a scheme for generation of arbitrary coherent superposition of vortex states in Bose-Einstein condensates (BEC) using the orbital angular momentum (OAM) states of light. We devise a scheme to generate coherent superpositions of two counter-rotating ... More
The creation of large photon-number path entanglement conditioned on photodetectionDec 01 2001Jan 23 2003Large photon-number path entanglement is an important resource for enhanced precision measurements and quantum imaging. We present a general constructive protocol to create any large photon number path-entangled state based on the conditional detection ... More
High precision Optical AC Magnetometry using Dynamical DecouplingJul 23 2018We propose a magnetometer for the precise measurement of AC magnetic fields that uses a Terbium-doped optical fiber with half-waveplates built into it at specified distances. Our scheme uses an open-loop quantum control technique called dynamical decoupling ... More
Spontaneous parametric down-conversion photon sources are scalable in the asymptotic limit for boson-samplingJul 31 2013Apr 14 2014Boson-sampling has emerged as a promising avenue towards post-classical optical quantum computation, and numerous elementary demonstrations have recently been performed. Spontaneous parametric down-conversion (SPDC) is the mainstay for single-photon state ... More
Non-Gaussian entangled states and quantum teleportation of Schrödinger-cat statesJun 13 2013Feb 28 2015In continuous-variable quantum information, non-Gaussian entangled states that are obtained from Gaussian entangled states via photon subtraction are known to contain more entanglement. This makes them better resources for quantum information processing ... More
Practical quantum repeaters with linear optics and double-photon gunsMar 27 2002We show how to create practical, efficient, quantum repeaters, employing double-photon guns, for long-distance optical quantum communication. The guns create polarization-entangled photon pairs on demand. One such source might be a semiconducter quantum ... More
Parity Measurement is Sufficient for Phase Estimation at the Quantum Cramer-Rao Bound for Path-Symmetric StatesJul 02 2012In this letter, we show that for all the so-called path-symmetric states, the measurement of parity of photon number at the output of an optical interferometer achieves maximal phase sensitivity at the quantum Cramer-Rao bound. Such optimal phase sensitivity ... More
Maxwell Duality, Lorentz Invariance, and Topological PhaseJun 04 1999Aug 06 1999We discuss the Maxwell electromagnetic duality relations between the Aharonov-Bohm, Aharonov-Casher, and He-McKellar-Wilkens topological phases, which allows a unified description of all three phenomena. We also elucidate Lorentz transformations that ... More
Strong Violations of Bell-type Inequalities for Path-Entangled Number StatesOct 20 2006Sep 24 2007We show that nonlocal correlation experiments on the two spatially separated modes of a maximally path-entangled number state may be performed and lead to a violation of a Clauser-Horne Bell inequality for any finite photon number N. We present also an ... More
From Linear Optical Quantum Computing to Heisenberg-Limited InterferometryDec 19 2003Apr 07 2004The working principles of linear optical quantum computing are based on photodetection, namely, projective measurements. The use of photodetection can provide efficient nonlinear interactions between photons at the single-photon level, which is technically ... More
Optical Communication Noise Rejection Using Correlated PhotonsApr 29 2003This paper describes a completely new way to perform noise rejection using a two-photon sensitive detector and taking advantage of the properties of correlated photons to improve an optical communications link in the presence of uncorrelated noise. In ... More
Quantum Enhanced Magnetometer with Low-Frequency SqueezingFeb 17 2012Jul 11 2012We report the demonstration of a magnetometer with noise-floor reduction below the shot-noise level. This magnetometer, based on a nonlinear magneto-optical rotation effect, is enhanced by the injection of a squeezed vacuum state into its input. The noise ... More
Quantum lithography, entanglement and Heisenberg-limited parameter estimationFeb 12 2004We explore the intimate relationship between quantum lithography, Heisenberg-limited parameter estimation and the rate of dynamical evolution of quantum states. We show how both the enhanced accuracy in measurements and the increased resolution in quantum ... More
Reducing the number of ancilla qubits and the gate count required for creating large controlled operationsApr 19 2013In this paper we show that it is possible to adapt a qudit scheme for creating a controlled-Toffoli created by Ralph et al. [Phys. Rev. A 75 011213] to be applicable to qubits. While this scheme requires more gates than standard schemes for creating large ... More
Selective Near Perfect Light Absorbtion by Graphene Monolayer Using Aperiodic Multilayer MicrostructuresFeb 06 2018We investigate 1D aperiodic multilayer microstructures in order to achieve near total absorption in preselected wavelengths in a graphene monolayer. Our structures are designed by a genetic optimization algorithm coupled to a transfer matrix code. Coupled ... More
Effects of Phase Fluctuations on Phase Sensitivity and Visibility of Path-Entangled Photon Fock StatesJul 17 2013Aug 29 2013We study effects of phase fluctuations on phase sensitivity and visibility of a class of robust path-entangled photon Fock states (known as mm' states) as compared to the maximally path-entangled N00N states in presence of realistic phase fluctuations ... More
Ultra-Stable Matter-Wave Gyroscopy with Counter-Rotating Vortex Superpositions in Bose-Einstein CondensatesJul 07 2009Matter-wave interferometers are, in principle, orders of magnitude more sensitive than their optical counterparts. Nevertheless, creation of matter-wave currents to achieve such a sensitivity is a continuing challenge. Here, we propose the use of Optical ... More
Entangled Fock states for Robust Quantum Optical Metrology, Imaging, and SensingMay 02 2008Aug 15 2008We propose a class of path-entangled photon Fock states for robust quantum optical metrology, imaging, and sensing in the presence of loss. We model propagation loss with beam-splitters and derive a reduced density matrix formalism from which we examine ... More
Coherent-Light Boosted, Super-Sensitive, Quantum InterferometryNov 30 2009Jun 14 2015We present in this letter a scheme for optical interferometry. We utilize coherent-beam-stimulated two-mode squeezed light, which interacts with a phase shifter and is then squeezed again before detection. Our theoretical device has the potential to reach ... More
Distributed entanglement as a probe for the quantum structure of spacetimeJun 12 2002Simultaneity is a well-defined notion in special relativity once a Minkowski metric structure is fixed on the spacetime continuum (manifold) of events. In quantum gravity, however, the metric is not expected to be a fixed, classical structure, but a fluctuating ... More
Super-Resolving Quantum Radar: Coherent-State Sources with Homodyne Detection Suffice to Beat the Diffraction LimitMay 17 2013Feb 17 2014There has been much recent interest in quantum metrology for applications to sub-Raleigh ranging and remote sensing such as in quantum radar. For quantum radar, atmospheric absorption and diffraction rapidly degrades any actively transmitted quantum states ... More
Phase estimation with two-mode squeezed-vacuum and parity detection restricted to finite resourcesOct 07 2011Sep 09 2013A recently proposed phase-estimation protocol that is based on measuring the parity of a two-mode squeezed-vacuum state at the output of a Mach-Zehnder interferometer shows that Cram\'{e}r-Rao bound sensitivity can be obtained [P.\ M.\ Anisimov, et al., ... More
Objectively discerning Autler-Townes Splitting from Electromagnetically Induced TransparencyFeb 02 2011Jun 20 2011Autler-Townes splitting (ATS) and electromagnetically-induced transparency (EIT) both yield transparency in an absorption profile, but only EIT yields strong transparency for a weak pump field due to Fano interference. Empirically discriminating EIT from ... More
Arbitrary Coherent Superpositions of Quantized Vortices in Bose-Einstein Condensates from Orbital Angular Momentum Beams of LightMar 18 2008We recently proposed a scheme for the creation of coherent superpositions of vortex states in Bose-Einstein condensates (BEC) using orbital angular momentum (OAM) states of light [Phys. Rev. Lett. 95, 173601 (2005)]. Here we discuss further technical ... More
Suitability versus fidelity for rating single-photon gunsJun 28 2002Apr 01 2003The creation of specified quantum states is important for most, if not all, applications in quantum computation and communication. The quality of the state preparation is therefore an essential ingredient in any assessment of a quantum-state gun. We show ... More
Linear optics and projective measurements alone suffice to create large-photon-number path entanglementSep 17 2001Sep 18 2001We propose a method for preparing maximal path entanglement with a definite photon number N, larger than two, using projective measurements. In contrast with the previously known schemes, our method uses only linear optics. Specifically, we exhibit a ... More
A Quantum Phase Representation of Heisenberg Limits and a Minimally Resourced Quantum Phase EstimatorMar 10 2014Sep 08 2014Within the quantum phase representation we derive Heisenberg limits, in closed form, for N00N states and two other classes of states that can perform better in terms of local performance metrics relevant for multiply-peaked distributions. One of these ... More
Alternate Scheme for Optical Cluster-State Generation without Number-Resolving Photon DetectorsOct 16 2006May 22 2007We design a controlled-phase gate for linear optical quantum computing by using photodetectors that cannot resolve photon number. An intrinsic error-correction circuit corrects errors introduced by the detectors. Our controlled-phase gate has a 1/4 success ... More
High-fidelity linear optical quantum computing with polarization encodingAug 15 2005Sep 23 2005We show that the KLM scheme [Knill, Laflamme and Milburn, Nature {\bf 409}, 46] can be implemented using polarization encoding, thus reducing the number of path modes required by half. One of the main advantages of this new implementation is that it naturally ... More
Generating Entangled Photons from the Vacuum by Accelerated Measurements: Quantum Information Theory Meets the Unruh-Davies EffectMay 10 2007Sep 26 2007Building on the well-known Unruh-Davies effect, we examine the effects of projective measurements and quantum communications between accelerated and stationary observers. We find that the projective measurement by a uniformly accelerated observer can ... More
A non-degenerate optical parametric oscillator as a high-flux source for quantum lithographyMar 25 2009We investigate the use of a non-degenerate parametric oscillator (NDPO) as a source for quantum lithography, for which the light can have high-flux and strong non-classical features. This builds on the proposal of Boto, et al. [A. N. Boto, et al., PRL ... More
Two-Photon Interferometry for High-Resolution ImagingApr 23 2001Jun 13 2001We discuss advantages of using non-classical states of light for two aspects of optical imaging: creating of miniature images on photosensitive substrates, which constitutes the foundation for optical lithography, and imaging of micro objects. In both ... More
Boson sampling with displaced single-photon Fock states versus single-photon-added coherent states---The quantum-classical divide and computational-complexity transitions in linear opticsFeb 03 2014Feb 27 2015Boson sampling is a specific quantum computation, which is likely hard to implement efficiently on a classical computer. The task is to sample the output photon number distribution of a linear optical interferometric network, which is fed with single-photon ... More
Sampling arbitrary photon-added or photon-subtracted squeezed states is in the same complexity class as boson samplingJun 30 2014Feb 23 2015Boson sampling is a simple model for non-universal linear optics quantum computing using far fewer physical resources than universal schemes. An input state comprising vacuum and single photon states is fed through a Haar-random linear optics network ... More
An introduction to boson-samplingJun 26 2014Boson-sampling is a simplified model for quantum computing that may hold the key to implementing the first ever post-classical quantum computer. Boson-sampling is a non-universal quantum computer that is significantly more straightforward to build than ... More
On the connection between quantum nonlocality and phase sensitivity of two-mode entangled Fock state superpositionsOct 04 2013Aug 23 2015In two-mode interferometry, for a given total photon number $N$, entangled Fock state superpositions of the form $(|N-m\rangle_a|m\rangle_b+e^{i (N-2m)\phi}|m\rangle_a|N-m\rangle_b)/\sqrt{2}$ have been considered for phase estimation. Indeed all such ... More
Scalable boson-sampling with time-bin encoding using a loop-based architectureMar 17 2014We present an architecture for arbitrarily scalable boson-sampling using two nested fiber loops. The architecture has fixed experimental complexity, irrespective of the size of the desired interferometer, whose scale is limited only by fiber and switch ... More
Sampling generalized cat states with linear optics is probably hardOct 01 2013Dec 21 2014Boson-sampling has been presented as a simplified model for linear optical quantum computing. In the boson-sampling model, Fock states are passed through a linear optics network and sampled via number-resolved photodetection. It has been shown that this ... More
General linear-optical quantum state generation scheme: Applications to maximally path-entangled statesDec 18 2006Jan 02 2008We introduce schemes for linear-optical quantum state generation. A quantum state generator is a device that prepares a desired quantum state using product inputs from photon sources, linear-optical networks, and postselection using photon counters. We ... More
Relativity of quantum states in entanglement swapping: Violation of Bell's inequality with no entanglementJun 06 2018The entanglement swapping protocol is analyzed in a relativistic setting, where shortly after the entanglement swapping is performed, a Bell violation measurement is performed. From an observer in the laboratory frame, a Bell violation is observed due ... More
Linear Optical Quantum Metrology with Single Photons: Exploiting Spontaneously Generated Entanglement to Beat the Shot-Noise LimitJan 06 2015May 04 2015Quantum number-path entanglement is a resource for super-sensitive quantum metrology and in particular provides for sub-shotnoise or even Heisenberg-limited sensitivity. However, such number-path entanglement has thought to have been resource intensive ... More
Quantum Clock Synchronization Based on Shared Prior EntanglementApr 27 2000Jun 30 2000We demonstrate that two spatially separated parties (Alice and Bob) can utilize shared prior quantum entanglement, and classical communications, to establish a synchronized pair of atomic clocks. In contrast to classical synchronization schemes, the accuracy ... More
Implementing Scalable Boson Sampling with Time-Bin Encoding: Analysis of Loss, Mode Mismatch, and Time JitterJul 26 2015It was recently shown by Motes, Gilchrist, Dowling & Rohde [PRL 113, 120501 (2014)] that a time-bin encoded fiber-loop architecture can implement an arbitrary passive linear optics transformation. This was shown in the case of an ideal scheme whereby ... More
A Quantum Optics Argument for the #P-hardness of a Class of Multidimensional IntegralsJul 18 2016Matrix permanents arise naturally in the context of linear optical networks fed with nonclassical states of light. In this letter we tie the computational complexity of a class of multi-dimensional integrals to the permanents of large matrices using a ... More
Boson Sampling Private-Key Quantum CryptographyMay 08 2019We introduce a quantum private-key encryption protocol based on multi-photon interference in linear optics networks. The scheme builds upon Boson Sampling, and we show that it is hard to break, even for a quantum computer. We present an information-theoretic ... More
Fundamental precision limit of a Mach-Zehnder interferometric sensor when one of the inputs is the vacuumMay 26 2017In the lore of quantum metrology, one often hears (or reads) the following no-go theorem: If you put vacuum into one input port of a balanced Mach-Zehnder Interferometer, then no matter what you put into the other input port, and no matter what your detection ... More
Coherent and Squeezed Vacuum Light Interferometry: Parity detection hits the Heisenberg limitMay 13 2011Jun 02 2011The interference between coherent and squeezed vacuum light can produce path entangled states with very high fidelities. We show that the phase sensitivity of the above interferometric scheme with parity detection saturates the quantum Cramer-Rao bound, ... More
Towards Linear Optical Quantum ComputersFeb 13 2004Scalable quantum computation with linear optics was considered to be impossible due to the lack of efficient two-qubit logic gates, despite its ease of implementation of one-qubit gates. Two-qubit gates necessarily need a nonlinear interaction between ... More
Experimental sub-Rayleigh resolution by an unseeded high-gain optical parametric amplifier for quantum lithographyJan 23 2008Quantum lithography proposes to adopt entangled quantum states in order to increase resolution in interferometry. In the present paper we experimentally demonstrate that the output of a high-gain optical parametric amplifier can be intense yet exhibits ... More
Resolution and sensitivity of a Fabry-Perot interferometer with a photon-number-resolving detectorMay 07 2009Aug 31 2009With photon-number resolving detectors, we show compression of interference fringes with increasing photon numbers for a Fabry-Perot interferometer. This feature provides a higher precision in determining the position of the interference maxima compared ... More
Review article: Linear optical quantum computingDec 09 2005Mar 14 2006Linear optics with photon counting is a prominent candidate for practical quantum computing. The protocol by Knill, Laflamme, and Milburn [Nature 409, 46 (2001)] explicitly demonstrates that efficient scalable quantum computing with single photons, linear ... More
An All Linear Optical Quantum Memory Based on Quantum Error CorrectionJun 13 2003Jun 13 2003When photons are sent through a fiber as part of a quantum communication protocol, the error that is most difficult to correct is photon loss. Here, we propose and analyze a two-to-four qubit encoding scheme, which can recover the loss of one qubit in ... More
Conclusive Precision Bounds for SU(1,1) InterferometersOct 18 2018In this paper, we revisit the quantum Fisher information (QFI) calculation in SU(1,1) interferometer considering different phase configurations. When one of the input modes is a vacuum state, we show by using phase averaging, different phase configurations ... More
Coherent-state optical qudit cluster state generation and teleportation via homodyne detectionDec 29 2010Defining a computational basis of pseudo-number states, we interpret a coherent state of large amplitude, $|\alpha|\gg\frac{d}{2\pi}$, as a qudit --- a $d$-level quantum system --- in a state that is an even superposition of $d$ pseudo-number states. ... More
Quantized Nonlinear Gaussian-Beam Dynamics $-$ Tailoring Multimode Squeezed-Light GenerationJun 11 2018Oct 18 2018We present a general, second quantization procedure for multi-transverse-spatial mode Gaussian beam dynamics in nonlinear interactions. Previous treatments have focused on the spectral density and angular distribution of spatial modes. Here we go a layer ... More
Sagnac interferometry with coherent vortex superposition states in exciton-polariton condensatesJun 25 2015Oct 12 2015We investigate prospects of using counter-rotating vortex superposition states in non-equilibrium exciton-polariton Bose-Einstein condensates for the purposes of Sagnac interferometry. We first investigate the stability of vortex-antivortex superposition ... More
Adaptive phase estimation with two-mode squeezed-vacuum and parity measurementSep 15 2016A proposed phase-estimation protocol based on measuring the parity of a two-mode squeezed-vacuum state at the output of a Mach-Zehnder interferometer shows that the Cram\'{e}r-Rao sensitivity is sub-Heisenberg [Phys.\ Rev.\ Lett.\ {\bf104}, 103602 (2010)]. ... More
Coherent Communication with Linear OpticsSep 25 2007We show how to implement several continuous-variable coherent protocols with linear optics. Noise can accumulate when implementing each coherent protocol with realistic optical devices. Our analysis bounds the level of noise accumulation. We highlight ... More
Quantum Information transmissionJun 25 2011Feb 21 2012We present a scheme of quantum information transmission, which transmits the quantum information contained in a single qubit via the quantum correlation shared by two parties (a two-qubit channel), whose quantum discord is non-zero. We demonstrate that ... More
Sub-shot-noise-limited phase estimation via SU(1,1) interferometer with thermal statesNov 09 2017We theoretically study the phase sensitivity of an SU(1,1) interferometer with a thermal state and squeezed vacuum state as inputs and parity detection as measurement. We find that phase sensitivity can beat the shot-noise limit and approaches the Heisenberg ... More
Improving photon detector efficiency using a high-fidelity optical CNOT gateAug 12 2013Jan 07 2015A significant problem for optical quantum computing is inefficient, or inaccurate photo-detectors. It is possible to use CNOT gates to improve a detector by making a large cat state then measuring every qubit in that state. In this paper we develop a ... More
Quantum Interferometric SensorsJul 15 2005Quantum entanglement has the potential to revolutionize the entire field of interferometric sensing by providing many orders of magnitude improvement in interferometer sensitivity. The quantum-entangled particle interferometer approach is very general ... More
Exploiting the quantum Zeno effect to beat photon loss in linear optical quantum information processorsAug 03 2004We devise a new technique to enhance transmission of quantum information through linear optical quantum information processors. The idea is based on applying the Quantum Zeno effect to the process of photon absorption. By frequently monitoring the presence ... More
Gaussian Beam-Propagation Theory for Nonlinear Optics - Featuring an Exact Treatment of Orbital Angular Momentum TransferFeb 03 2017Apr 25 2017We present a general, Gaussian spatial mode propagation formalism for describing the generation of higher order multi-spatial-mode beams generated during nonlinear interactions. Furthermore, to implement the theory, we simulate optical angular momentum ... More
Parity Detection in Quantum Optical Metrology Without Number Resolving DetectorsJul 23 2010Aug 09 2012We present a method of directly obtaining the parity of a Gaussian state of light without recourse to photon-number counting. The scheme uses only a simple balanced homodyne technique, and intensity correlation. Thus interferometric schemes utilizing ... More
Optimizing the Multi-Photon Absorption Properties of N00N StatesAug 10 2009In this paper we examine the N-photon absorption properties of "N00N" states, a subclass of path entangled number states. We consider two cases. The first involves the N-photon absorption properties of the ideal N00N state, one that does not include spectral ... More
An Invisible Quantum TripwireFeb 17 2010Oct 01 2010We present here a quantum tripwire, which is a quantum optical interrogation technique capable of detecting an intrusion with very low probability of the tripwire being revealed to the intruder. Our scheme combines interaction-free measurement with the ... More
Super-Resolution at the Shot-Noise Limit with Coherent States and Photon-Number-Resolving DetectorsJul 14 2009Jul 14 2009There has been much recent interest in quantum optical interferometry for applications to metrology, sub-wavelength imaging, and remote sensing, such as in quantum laser radar (LADAR). For quantum LADAR, atmospheric absorption rapidly degrades any quantum ... More
The Generation of Super-Resolving Single-Photon Path-Entangled StateOct 21 2013In this paper, we propose two protocols for generating super-resolving \textit{single-photon} path-entangled states from general maximally path-entangled N00N states. We also show that both protocols generate the desired state with different probabilities ... More
Entanglement-Seeded-Dual Optical Parametric Amplification: Applications to Quantum Communication, Imaging, and MetrologyApr 10 2008Apr 10 2008The study of optical parametric amplifiers (OPAs) has been successful in describing and creating nonclassical light for use in fields such as quantum metrology and quantum lithography [Agarwal, et al., J. Opt. Soc. Am. B, 24, 2 (2007)]. In this paper ... More
Optimizing Optical Quantum Logic Gates using Genetic AlgorithmsAug 10 2007Sep 04 2007We introduce the method of using an annealing genetic algorithm to the numerically complex problem of looking for quantum logic gates which simultaneously have highest fidelity and highest success probability. We first use the linear optical quantum nonlinear ... More
Maximal Success Probabilities of Linear-Optical Quantum GatesAug 14 2008Nov 22 2008Numerical optimization is used to design linear-optical devices that implement a desired quantum gate with perfect fidelity, while maximizing the success rate. For the 2-qubit CS (or CNOT) gate, we provide numerical evidence that the maximum success rate ... More
Optimized aperiodic broadband thermal emitters for use as light bulb filamentsMay 03 2016May 23 2016We present optimized aperiodic structures for use as broadband thermal incandescent emitters which are capable of increasing the emittance by nearly a factor of two over the visible wavelength range when compared to bulk tungsten. These aperiodic multilayer ... More
Enhanced signal-to-noise ratio in Hanbury Brown Twiss interferometry by parametric amplificationDec 07 2017The Hanbury Brown Twiss (HBT) interferometer was proposed to observe intensity correlations of starlight to measure a star's angular diameter. As the intensity of light that reaches the detector from a star is very weak, one cannot usually get a workable ... More
Quantum random walks with multiphoton interference and high order correlation functionsDec 16 2011Apr 11 2013We show a simulation of quantum random walks with multiple photons using a staggered array of 50/50 beam splitters with a bank of detectors at any desired level. We discuss the multiphoton interference effects that are inherent to this setup, and introduce ... More