Latest in quant-ph

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Unfolding as Quantum AnnealingAug 22 2019High-energy physics is replete with hard computational problems and it is one of the areas where quantum computing could be used to speed up calculations. We present an implementation of likelihood-based regularized unfolding on a quantum computer. The ... More
Reflections on Virasoro circuit complexity and Berry phaseAug 22 2019Recently, the notion of circuit complexity defined in symmetry group manifolds has been related to geometric actions which generally arise in the coadjoint orbit method in representation theory and play an important role in geometric quantization. On ... More
Cavity electromechanics with parametric mechanical drivingAug 22 2019Microwave optomechanical circuits have been demonstrated in the past years to be extremely powerfool tools for both, exploring fundamental physics of macroscopic mechanical oscillators as well as being promising candidates for novel on-chip quantum limited ... More
Applying machine learning optimization methods to the production of a quantum gasAug 22 2019We apply three machine learning strategies to optimize the atomic cooling processes utilized in the production of a Bose-Einstein condensate (BEC). For the first time, we optimize both laser cooling and evaporative cooling mechanisms simultaneously. We ... More
All-microwave holonomic control of an electron-nuclear two-qubit register in diamondAug 22 2019We present a theoretical scheme that allows to perform a universal set of holonomic gates on a two qubit register, formed by a $^{13}$C nuclear spin coupled to the electron spin of a nitrogen-vacancy center in diamond. Strong hyperfine interaction between ... More
Improving the dynamics of quantum sensors with reinforcement learningAug 22 2019Recently proposed quantum-chaotic sensors achieve quantum enhancements in measurement precision by applying nonlinear control pulses to the dynamics of the quantum sensor while using classical initial states that are easy to prepare. Here, we use the ... More
Two-photon blockade and photon-induced tunneling generated by squeezingAug 22 2019Inspired by the recent experiment of Hamsen \emph{et al.} [Phys. Rev. Lett. 118, 133604 (2017)], which demonstrated two-photon blockade in a driven nonlinear system (composed of a harmonic cavity with a driven atom), we show that two-photon blockade and ... More
Supervised learning with a quantum classifier using a multi-level systemAug 22 2019We propose a quantum classifier, which can classify data under the supervised learning scheme using a quantum feature space. The input feature vectors are encoded in a single qu$N$it (a $N$ level quantum system), as opposed to more commonly used entangled ... More
Signatures of Many-Particle InterferenceAug 22 2019This Tutorial will introduce the mathematical framework for describing systems of identical particles, and explain the notion of indistinguishability. We will then focus our attention on dynamical systems of free particles and formally introduce the concept ... More
Nonzero temperature dynamics of a repulsive two-component Fermi gasAug 22 2019We study spin-dipole oscillations of a binary fermionic mixture at nonzero temperatures. We apply the atomic-orbital method combined with the Monte Carlo technique based sampling to probe finite temperatures. Our results agree quantitatively with recent ... More
Variational spin-squeezing algorithms on programmable quantum sensorsAug 22 2019Arrays of atoms trapped in optical tweezers combine features of programmable analog quantum simulators with atomic quantum sensors. Here we propose variational quantum algorithms, tailored for tweezer arrays as programmable quantum sensors, capable of ... More
Nonreciprocal transition between two nondegenerate energy levelsAug 22 2019Stimulated emission and absorption are two fundamental processes of light-matter interaction, and the coefficients of the two processes should be equal in general. However, we will describe a generic method to realize significant difference between the ... More
Pretty simple bounds on quantum state discriminationAug 22 2019We show that the quantum measurement known as the pretty good measurement can be used to identify an unknown quantum state picked from any set of $n$ mixed states that have pairwise fidelities upper-bounded by a constant below 1, given $O(\log n)$ copies ... More
Conditional Teleportation of Quantum-Dot Spin StatesAug 22 2019Among the different experimental platforms for quantum information processing, individual electron spins in semiconductor quantum dots stand out for their long coherence times and potential for scalable fabrication. The past years have witnessed substantial ... More
Quantum key distribution with correlated sourcesAug 22 2019Implementation security is a critical problem in quantum key distribution (QKD). With the advent of measurement-device-independent QKD, all security loopholes of the measurement unit have been closed. Securing the source, however, remains an elusive issue. ... More
Electric and Magnetic Field Nano-Sensing Using a New, Atomic-like Qubit in a Carbon NanotubeAug 22 2019Quantum sensing techniques have been successful in pushing the sensitivity limits in numerous fields, and hold great promise for scanning probes that study nano-scale devices and novel materials. However, forming a nano-scale qubit that is simple and ... More
Apoptosis of moving, non-orthogonal basis functions in many-particle quantum dynamicsAug 22 2019Due to the exponential increase of the numerical effort with the number of degrees of freedom, moving basis functions have a long history in quantum dynamics. In addition, spawning of new basis functions is routinely applied. Here we advocate the opposite ... More
Quantum Algorithms for Portfolio OptimizationAug 22 2019We develop the first quantum algorithm for the constrained portfolio optimization problem. The algorithm has running time $\widetilde{O} \left( n\sqrt{r} \frac{\zeta \kappa}{\delta^2} \log \left(1/\epsilon\right) \right)$, where $r$ is the number of positivity ... More
Optimal Control for the Quantum Simulation of Nuclear DynamicsAug 22 2019We propose a method for enacting the unitary time propagation of two interacting neutrons at leading order of chiral effective field theory by efficiently encoding the nuclear dynamics into a single multi-level quantum device. The emulated output of the ... More
Genuine Measure of Multipartite Entanglement and its Monogamy RelationAug 22 2019To quantify entanglement, many entanglement measures have been proposed so far. However, much less is known in the multipartite case, and even the existing multipartite measures are still studied by virtue of the postulates of bipartite case. Namely, ... More
Electron-positron pair production in frequency modulated laser fieldsAug 22 2019The momentum spectrum and the number density of created electron-positron pairs in a frequency modulated laser field are investigated using quantum kinetic equation. It is found that the momentum spectrum presents obvious interference pattern. This is ... More
Dynamical behaviour of coupled atom-cavity systems in the single excitation limitAug 22 2019We investigate the time evolution of the photon-detection probability at various output ports of an all-fiber coupled cavity-quantum-electrodynamics (cavity-QED) system. The setup consists of two atoms trapped separately in the field of two nanofiber ... More
Weak Gravitational Field Effects on Optical Bell TestsAug 22 2019The technological refinement of experimental techniques has recently allowed the generation of two-photon polarization entangled states at low Earth orbit, which have been subsequently applied to quantum communications. This achievement paves the way ... More
Exact results for the boundary energy of one-dimensional bosonsAug 22 2019We study bosons in a one-dimensional hard wall box potential. In the case of contact interaction, the system is exactly solvable by Bethe ansatz, as first shown by Gaudin in 1971. Although contained in the exact solution, the boundary energy for this ... More
Flexible S-money token schemesAug 21 2019S-money [Proc. R. Soc. A 475, 20190170 (2019)] schemes define virtual tokens designed for networks with relativistic or other trusted signalling constraints. The tokens allow near-instant verification and guarantee unforgeability without requiring quantum ... More
Quantum Neimark-Sacker bifurcationAug 21 2019Recently, it has been demonstrated that asymptotic states of open quantum system can undergo qualitative changes resembling pitchfork, saddle-node, and period doubling classical bifurcations. Here, making use of the periodically modulated open quantum ... More
Normal modes for N identical particles: A study of the evolution of collective behavior from few-body to many-bodyAug 21 2019Normal mode dynamics are ubiquitous underlying the motions of diverse systems from rotating stars to crystal structures. These behaviors are composed of simple collective motions of particles which move with the same frequency and phase, thus encapsulating ... More
Experimental investigation of Markovian and non-Markovian channel additionAug 21 2019The study of memory effects in quantum channels helps in developing characterization methods for open quantum systems and strategies for quantum error correction. Two main sets of channels exist, corresponding to system dynamics with no memory (Markovian) ... More
Closing gaps of a quantum advantage with short-time Hamiltonian dynamicsAug 21 2019Demonstrating a quantum computational speedup is a crucial milestone for near-term quantum technology. Recently, quantum simulation architectures have been proposed that have the potential to show such a quantum advantage, based on commonly made assumptions. ... More
The Classical Complexity of Gaussian Boson SamplingAug 21 2019We introduce an exact classical algorithm for simulating Gaussian Boson Sampling (GBS). The complexity of the algorithm is exponential in the number of photons detected, which is itself a random variable. For a fixed number of modes, the complexity is ... More
Measurement reduction in variational quantum algorithmsAug 21 2019Variational quantum algorithms are promising applications of noisy intermediate-scale quantum (NISQ) computers. These algorithms consist of a number of separate prepare-and-measure experiments that estimate terms in the Hamiltonian. The number of separate ... More
Random Quantum BatteriesAug 21 2019Quantum nano-devices are fundamental systems in quantum thermodynamics that have been the subject of profound interest in recent years. Among these, quantum batteries play a very important role. In this paper we lay down a theory of random quantum batteries ... More
Half-integer quantized response in strongly driven quantum systemsAug 21 2019A spin strongly driven by two incommensurate tones can pump energy from one drive to the other at a quantized average rate, in close analogy with the quantum Hall effect. The quantized pumping is a pre-thermal effect with a lifetime that diverges as the ... More
Many-body systems as resources for universal fault tolerant quantum computationAug 21 2019A universal quantum computer will inevitably rely on error correction to be fault tolerant. Most error correcting schemes are based on stabilizer circuits which fail to provide universal quantum computation. An extra quantum resource, in the form of magic ... More
Automated quantum programming via reinforcement learning for combinatorial optimizationAug 21 2019We develop a general method for incentive-based programming of hybrid quantum-classical computing systems using reinforcement learning, and apply this to solve combinatorial optimization problems on both simulated and real gate-based quantum computers. ... More
Measurement-induced criticality in random quantum circuitsAug 21 2019We investigate the critical behavior of the entanglement transition induced by projective measurements in (Haar) random unitary quantum circuits. Using a replica approach, we map the calculation of the entanglement entropies in such circuits onto a two-dimensional ... More
Generating photon-added states without adding a photonAug 21 2019We show that a continuous range of nonclassical states of light can be generated using conditional measurements on the idler mode of an optical parametric amplifier. The output state is prepared by introducing a coherent state in the signal mode of the ... More
Enhancing quantum control by improving shape pulse generationAug 21 2019Most quantum processors requires pulse sequences for controlling quantum states. Here, we present an alternative algorithm for computing an optimal pulse sequence in order to perform a specific task, being an implementation of a quantum gate or a quantum ... More
Efficient Encoding of Matrix Product States into Quantum Circuits of One- and Two-Qubit GatesAug 21 2019Matrix product state (MPS) belongs to the most important mathematical models in, for example, condensed matter physics and quantum information sciences. However, to realize an $N$-qubit MPS with large $N$ and large entanglement on a quantum platform is ... More
An Optimized Quantum Maximum or Minimum Searching Algorithm and its CircuitsAug 21 2019Finding a maximum or minimum is a fundamental building block in many mathematical models. Compared with classical algorithms, Durr, Hoyer's quantum algorithm (DHA) achieves quadratic speed. However, its key step, the quantum exponential searching algorithm ... More
Full Quantum Eigensolver for Quantum Chemistry SimulationsAug 21 2019The quantum simulation of quantum chemistry, as one of the most compelling applications of quantum computing, is potential importance in many areas ranging from materials science to biochemistry and condensed physics. Here, we propose a quantum gradient ... More
Nonreciprocity and Unidirectional Invisibility in Cavity MagnonicsAug 21 2019We reveal the cooperative effect of coherent and dissipative magnon-photon couplings in an open cavity magnonic system, which leads to nonreciprocity with a considerably large isolation ratio and flexible controllability. Furthermore, we discover unidirectional ... More
Level anti-crossings of an NV center in diamond: Decoherence-free subspaces and 3D sensors of microwave magnetic fieldsAug 21 2019Nitrogen-vacancy (NV) centers in diamond have become an important tool for quantum technologies. All of these applications rely on long coherence times of electron and nuclear spins associated with these centers. Here, we study the energy level anti-crossings ... More
Spin-orbit-coupled quantum memory of a double quantum dotAug 21 2019The concept of quantum memory plays an incisive role in the quantum information theory. As confirmed by several recent rigorous mathematical studies, the quantum memory inmate in the bipartite system $\rho_{AB}$ can reduce uncertainty about the part $B$, ... More
Quantum heat transfer between nonlinearly-coupled bosonic and fermionic baths: an exactly solvable modelAug 21 2019The evolution of a quantum system towards thermal equilibrium is usually studied by approximate methods, which have their limits of validity and should be checked against analytically solvable models. In this paper, we propose an analytically solvable ... More
Timing-induced quantum collapse of wave-particle duality in a two-path interferometerAug 21 2019We propose an experiment of two-path interference in which the optical path difference between the two interferometer arms is much larger than the spatial spread of single-photon pulses, thereby enabling the "which-path" information of an individual photon ... More
Probing non-Hermitian Skin Effect and non-Bloch Phase TransitionsAug 21 2019In non-Hermitian crystals showing the non-Hermitian skin effect, ordinary Bloch band theory and Bloch topological invariants fail to correctly predict energy spectra, topological boundary states, and symmetry breaking phase transitions in systems with ... More
Ishibashi States, Topological Orders with Boundaries and Topological Entanglement Entropy II -- Cutting through the boundaryAug 21 2019We compute the entanglement entropy in a 2+1 dimensional topological order in the presence of gapped boundaries. Specifically, we consider entanglement cuts that cut through the boundaries. We argue that based on general considerations of the bulk-boundary ... More
The Complementary Information Principle of Quantum MechanicsAug 21 2019The uncertainty principle bounds the uncertainties about incompatible measurements, clearly setting quantum theory apart from the classical world. Its mathematical formulation via uncertainty relations, plays an irreplaceable role in quantum technologies. ... More
Characterising Quantum Devices at Scale with Custom Cryo-CMOSAug 21 2019We make use of a custom-designed cryo-CMOS multiplexer (MUX) to enable multiple quantum devices to be characterized in a single cool-down of a dilution refrigerator. Combined with a packaging approach that integrates cryo-CMOS chips and a hot-swappable, ... More
On the effects of an impurity in an Ising-$XXZ$ diamond chain on the thermal entanglement, on the quantum coherence and on the quantum teleportationAug 21 2019The effects of an impurity plaquette on the thermal quantum correlations measurement by the concurrence, on the quantum coherence quantified by the recently proposed $l_{1}$-norm of coherence and on the quantum teleportation in a Ising-$XXZ$ diamond chain ... More
Teleportation-based collective attacks in Gaussian quantum key distributionAug 21 2019In Gaussian quantum key distribution eavesdropping attacks are conventionally modeled through the universal entangling cloner scheme, which is based on the premise that the whole environment is under control of the adversary, i.e., the eavesdropper purifies ... More
Universal gates for protected superconducting qubits using optimal controlAug 20 2019We employ quantum optimal control theory to realize quantum gates for two protected superconducting circuits: the heavy-fluxonium qubit and the 0-$\pi$ qubit. Utilizing automatic differentiation facilitates the simultaneous inclusion of multiple optimization ... More
Distinguishing photons and anti-photons for highly-localised mirror HamiltoniansAug 20 2019Photons with well-defined energy are highly non-localised and occupy all available space in one dimension. On the other hand, optical elements, like mirrors, are highly-localised objects. To model the electromagnetic field in the presence of optical elements, ... More
Improving indistinguishability of single photons from colloidal quantum dots using nanocavitiesAug 20 2019Colloidal quantum dots have garnered active research interest as quantum emitters due to their robust synthesis process and straightforward integration with nanophotonic platforms. However, obtaining indistinguishable photons from the colloidal quantum ... More
Multiple Andreev reflections and Shapiro steps in a Ge-Si nanowire Josephson junctionAug 20 2019We present a Josephson junction based on a Ge-Si core-shell nanowire with transparent superconducting Al contacts, a building block which could be of considerable interest for investigating Majorana bound states, superconducting qubits and Andreev (spin) ... More
Isometric Tensor Network representation of string-net liquidsAug 20 2019Recently, a class of tensor networks called isometric tensor network states (isoTNS) was proposed which generalizes the canonical form of matrix product states to tensor networks in higher dimensions. While this ansatz allows for efficient numerical computations, ... More
The negativity contour: a quasi-local measure of entanglement for mixed statesAug 20 2019In this paper, we study the entanglement structure of mixed states in quantum many-body systems using the $\textit{negativity contour}$, a local measure of entanglement that determines which real-space degrees of freedom in a subregion are contributing ... More
The learnability scaling of quantum states: restricted Boltzmann machinesAug 20 2019Generative modeling with machine learning has provided a new perspective on the data-driven task of reconstructing quantum states from a set of qubit measurements. As increasingly large experimental quantum devices are built in laboratories, the question ... More
Prethermal Phases of Non-equilibrium Matter in Long-range Interacting SystemsAug 20 2019We prove the existence of non-equilibrium phases of matter in the prethermal regime of periodically-driven, long-range interacting systems, with power-law exponent $\alpha > d$, where $d$ is the dimensionality of the system. In this context, we predict ... More
On the transmission of quantum information through quantum fieldsAug 20 2019We investigate the quantum channel consisting of two localized quantum systems that communicate through a scalar quantum field. We choose a scalar field rather than a tensor or vector field, such as the electromagnetic field, in order to isolate the situation ... More
Interactions and charge transfer dynamics of an Al$^+$ ion immersed in ultracold Rb and Sr atomsAug 20 2019Atomic clocks based on an Al$^+$ ion sympathetically cooled by a laser-cooled alkaline-earth ion have achieved unprecedented accuracy. Here, we investigate theoretically interactions and charge transfer dynamics of an Al$^+$ ion immersed in an ultracold ... More
Information for efficiency: reconstructing compound objects by quantum imaging with higher-order correlation functionsAug 20 2019Quantum imaging generally leads to nonlinear estimation problems intractable for a larger number of problem parameters. We connect the features of the Fisher information with the parametric locality of the problem and build the efficient iterative scheme ... More
Nonlinear Limits to Optomechanical ThermometryAug 20 2019Optomechanical thermometry is a precise and reference-free method to measure absolute temperature. While pumping high optical power is needed to overcome noise and reduce the integration time, there is actually an upper limit to the useful optical power ... More
Machine learning configuration interaction for ab initio potential energy curvesAug 20 2019The concept of machine learning configuration interaction (MLCI) [J. Chem. Theory Comput. 2018, 14, 5739], where an artificial neural network (ANN) learns on the fly to select important configurations, is further developed so that accurate ab initio potential ... More
Randomness cost of masking quantum information and the information conservation lawAug 20 2019Masking quantum information, which is impossible without randomness as a resource, is a task that encodes quantum information into bipartite quantum state while forbidding local parties from accessing to that information. In this work, we disprove the ... More
Selective Interactions in the Quantum Rabi ModelAug 20 2019We demonstrate the emergence of selective $k$-photon interactions in the strong and ultrastrong coupling regimes of the quantum Rabi model with a Stark coupling term. In particular, we show that the interplay between rotating and counter-rotating terms ... More
A Hierarchy of Anyon Models Realised by Twists in Stacked Surface CodesAug 20 2019Braiding defects in topological stabiliser codes can be used to fault-tolerantly implement logical operations. Twists are defects corresponding to the end-points of domain walls and are associated with symmetries of the anyon model of the code. We consider ... More
Optomechanical refrigeration via multi-mode cold-damping feedbackAug 20 2019We provide a fully analytical treatment for the partial refrigeration of the thermal motion of a quantum mechanical resonator under the action of feedback. As opposed to standard cavity optomechanics where the aim is to isolate and cool a single mechanical ... More
Density Matrices for Derivational AmbiguityAug 20 2019Recent work on vector-based compositional natural language semantics has proposed the use of density matrices to model lexical ambiguity and (graded) entailment (e.g. Piedeleu et al 2015, Bankova et al 2016, Sadrzadeh et al 2018). Ambiguous word meanings, ... More
Quantum synchronization and correlation in bidirectionally and unidirectionally coupled optomechanical oscillatorsAug 20 2019Optically coupled optomechanical oscillators has turned out to be a versatile experimental resource for exploring optomechanical synchronizations and correlations. In this work, we investigate the phenomena of quantum synchronization and quantum correlations ... More
Geometry on the manifold of Gaussian quantum channelsAug 20 2019In the space of quantum channels, we establish the geometry that allows us to make statistical predictions about relative volumes of entanglement breaking channels among all the Gaussian quantum channels. The underlying metric is constructed using the ... More
Wavelength-scale errors in optical localization due to spin-orbit coupling of lightAug 20 2019The precise determination of the position of point-like emitters and scatterers using far-field optical imaging techniques is of utmost importance for a wide range of applications in medicine, biology, astronomy, and physics. Although the optical wavelength ... More
Strong Mechanical Squeezing for a Levitated Particle by Coherent ScatteringAug 20 2019Levitated particles are a promising platform for precision sensing of external perturbations and probing the boundary between quantum and classical worlds. A critical obstacle for these applications is the difficulty of generating nonclassical states ... More
Minimal degenerate CSS quantum code with low cost circuitAug 20 2019Error correction is of utmost necessity for large-scale quantum computing. Quantum error correcting codes can be degenerate, if more than one type of error can map the input state to the same error state. In this paper, we propose a 6-qubit degenerate ... More
Experimental demonstration of Cavity-Free Optical Isolators and Optical CirculatorsAug 20 2019Cavity free optical non reciprocity components, which have an inherent strong asymmetric interaction between their co and counter propagation direction, are key to produce such as optical isolators and circulators. According to the proposal presented ... More
Quantum-Kit: Simulating Shor's Factorization of 24-Bit Number on DesktopAug 20 2019Aug 21 2019Quantum-Kit is a graphical desktop application for quantum circuit simulations. Its powerful, memory-efficient computational engine enables large-scale simulations on a desktop. The ability to design hybrid circuits, with both quantum and classical bits ... More
Spin-selective Aharonov-Casher caging in a topological quantum networkAug 20 2019A periodic network of connected rhombii, mimicking a spintronic device, is shown to exhibit an intriguing spin selective extreme localization, when submerged in a uniform out of plane electric field. The topological Aharonov Casher phase acquired by a ... More
Coherent Epitaxial Semiconductor-Ferromagnetic Insulator InAs/EuS Interfaces: Band Alignment and Magnetic StructureAug 19 2019Hybrid semiconductor-ferromagnetic insulator heterostructures are interesting due to their tunable electronic transport, self-sustained stray field and local proximitized magnetic exchange. In this work, we present lattice matched hybrid epitaxy of semiconductor ... More
Extreme fluctuations of entropies in quantum systemsAug 19 2019The intuition that we have about entropy -- coming largely from the Boltzmann entropy -- is that the maximum entropy state is very close to the equilibrium state, while low entropy is associated with highly non-equilibrium states. It this paper, we investigate ... More
Beyond the Coulson-Fischer point: Characterizing single excitation CI and TDDFT for excited states in single bond dissociationsAug 19 2019Linear response time dependent density functional theory (TDDFT), which builds upon configuration interaction singles (CIS) and TD-Hartree-Fock (TDHF), is the most widely used class of excited state quantum chemistry methods and is often employed to study ... More
Deeply inelastic scattering structure functions on a hybrid quantum computerAug 19 2019We outline a strategy to compute deeply inelastic scattering structure functions using a hybrid quantum computer. Our approach takes advantage of the representation of the fermion determinant in the QCD path integral as a quantum mechanical path integral ... More
Cavity-assisted squeezing and entanglement: Non-adiabatic effects and optimal cavity-atomic ensemble matchingAug 19 2019We investigate theoretically quantum entanglement of light with the collective spin polarization of a cold atomic ensemble in cavity-assisted Raman schemes. Previous works concentrated mostly on the bad cavity limit where the signals are much longer than ... More
The Speed of Quantum Information Spreading in Chaotic SystemsAug 19 2019We present a general theory of quantum information propagation in chaotic quantum many-body systems. The generic expectation in such systems is that quantum information does not propagate in localized form; instead, it tends to spread out and scramble ... More
A uniform locally constant field approximation for photon-seeded pair productionAug 19 2019A challenge to upcoming experiments that plan to collide a particle beam with laser pulses of moderate intensity is how to correctly incorporate quantum effects into simulation frameworks. Using a uniform approach, we extend the widely-used locally constant ... More
Efficient quantum measurement of Pauli operatorsAug 19 2019Estimating the expectation value of an observable is a fundamental task in quantum computation. Unfortunately, it is often impossible to obtain such estimates directly, as the computer is restricted to measuring in a fixed computational basis. One common ... More
SU(2) non-Abelian gauge field theory in one dimension on digital quantum computersAug 19 2019An improved mapping of one-dimensional SU(2) non-Abelian gauge theory onto qubit degrees of freedom is presented. This new mapping allows for a reduced unphysical Hilbert space. Insensitivity to interactions within this unphysical space is exploited to ... More
Post-Newtonian Hamiltonian description of an atom in a weak gravitational fieldAug 19 2019We extend the systematic calculation of an approximately relativistic Hamiltonian for centre of mass and internal dynamics of an electromagnetically bound two-particle system by Sonnleitner and Barnett [1] to the case including a weak post-Newtonian gravitational ... More
Superconducting Josephson-based metamaterials for quantum-limited parametric amplification: a reviewAug 19 2019In the last few years, several groups have proposed and developed their own platforms demonstrating quantum-limited linear parametric amplification, with evident applications in quantum information and computation, electrical and optical metrology, radio ... More
Interacting Symmetry-Protected Topological Phases Out of EquilibriumAug 19 2019We show that the dynamics of generic isolated quantum systems admits a topological classification which captures universal features of many-body wavefunctions far from equilibrium. Specifically, we consider two short-ranged entangled wavefunctions to ... More
Object Tracking and Identification by Quantum RadarAug 19 2019Quantum Radar is a promising technology that could have a strong impact on the civilian and military realms. In this study we introduce a new concept design for implementing a Quantum Radar, based on the time and polarization correlations of the entangled ... More
Relativistic Quantum heat engine from uncertainty relation standpointAug 19 2019Established heat engines in quantum regime can be modeled with various quantum systems as working substances. For example, in the non-relativistic case, we can model the heat engine using infinite potential well as a working substance to evaluate the ... More
Bound on efficiency of heat engine from uncertainty relation viewpointAug 19 2019Quantum cycles in established heat engines can be modeled with various quantum systems as working substances. As for example, heat engine can be modeled with an infinite potential well as working substance to determine the efficiency and work done. However, ... More
On definition of quantum tomography via the Sobolev embedding theoremAug 19 2019We obtain sufficient conditions on kernels of quantum states under which Wigner functions, optical quantum tomograms and linking their formulas are correctly defined. Our approach is based upon the Sobolev embedding theorem. The transition probability ... More
From Classical Trajectories to Quantum Commutation RelationsAug 19 2019In describing a dynamical system, the greatest part of the work for a theoretician is to translate experimental data into differential equations. It is desirable for such differential equations to admit a Lagrangian and/or an Hamiltonian description because ... More
Quantum algorithms for Second-Order Cone Programming and Support Vector MachinesAug 19 2019Second order cone programs (SOCPs) are a class of structured convex optimization problems that generalize linear programs. We present a quantum algorithm for second order cone programs (SOCPs) based on a quantum variant of the interior point method. Our ... More
Tests of the Envelope Theory in One DimensionAug 19 2019The envelope theory is a simple technique to obtain approximate, but reliable, solutions of many-body systems with identical particles. The accuracy of this method is tested here for two systems in one dimension with pairwise forces. The first one is ... More
All tight correlation Bell inequalities have quantum violationsAug 19 2019It is by now well-established that there exist non-local games for which the best entanglement-assisted performance is not better than the best classical performance. Here we show in contrast that any two-player XOR game, for which the corresponding Bell ... More
Quantum Expectation-Maximization for Gaussian Mixture ModelsAug 19 2019The Expectation-Maximization (EM) algorithm is a fundamental tool in unsupervised machine learning. It is often used as an efficient way to solve Maximum Likelihood (ML) estimation problems, especially for models with latent variables. It is also the ... More
Quantum Expectation-Maximization AlgorithmAug 19 2019Clustering algorithms are a cornerstone of machine learning applications. Recently, a quantum algorithm for clustering based on the k-means algorithm has been proposed by Kerenidis, Landman, Luongo and Prakash. Based on their work, we propose a quantum ... More