Results for "Kavan Modi"

total 101took 0.23s
Operational approach to open dynamics and quantifying initial correlationsNov 29 2010Aug 08 2012A central aim of physics is to describe the dynamics of physical systems. Schrodinger's equation does this for isolated quantum systems. Describing the time evolution of a quantum system that interacts with its environment, in its most general form, has ... More
A pedagogical overview of quantum discordDec 30 2013Recent measures of nonclassical correlations are motivated by different notions of classicality and operational means. Quantum discord has received a great deal of attention in studies involving quantum computation, metrology, dynamics, many-body physics, ... More
A theoretical analysis of experimental open quantum dynamicsMar 16 2009In recent years there has been a significant development of the dynamical map formalism for initially correlated states of a system and its environment. Based on some of these results, we study quantum process tomography for initially correlated states ... More
Entropy bounds for quantum processes with initial correlationsMay 23 2014Dec 03 2015Quantum technology is progressing towards fast quantum control over systems interacting with small environments. Hence such technologies are operating in a regime where the environment remembers the system's past, and the applicability of complete-positive ... More
Unification of quantum and classical correlations and quantumness measuresApr 08 2011We give a pedagogical introduction to quantum discord. We the discuss the problem of separation of total correlations in a given quantum state into entanglement, dissonance, and classical correlations using the concept of relative entropy as a distance ... More
Correlations, operations and the second law of thermodynamicsNov 28 2014Completely positive trace preserving maps are essential for the formulation of the second law of thermodynamics. The dynamics of quantum systems, correlated with their environments, are in general not described by such maps. We explore how this issue ... More
Energetic fluctuations in an open quantum processJul 17 2014Relations similar to work and exchange fluctuations have been recently derived for open systems dynamically evolving in the presence of an ancilla. Extending these relations and constructing a non-equilibrium Helmholtz equation we derive a general expression ... More
Quantum Zeno and anti-Zeno effects in an Unstable System with Two Bound StateFeb 13 2005Sep 12 2007We analyze the experimental observations reported by Fischer et. al. [in Phys. Rev. Lett. 87, 040402 (2001)] by considering a system of coupled unstable bound quantum states A and B. The state B is coupled to a set of continuum states C. We investigate ... More
Criteria for measures of quantum correlationsAug 18 2011Jul 12 2012Entanglement does not describe all quantum correlations and several authors have shown the need to go beyond entanglement when dealing with mixed states. Various different measures have sprung up in the literature, for a variety of reasons, to describe ... More
The role of preparation in quantum process tomographyApr 29 2009In a recent letter one of us pointed out how differences in preparation procedures for quantum experiments can lead to non-trivial differences in the results of the experiment. The difference arise from the initial correlations between the system and ... More
Measuring the heat exchange of a quantum processJan 16 2014Aug 19 2014Very recently, interferometric methods have been proposed to measure the full statistics of work performed on a driven quantum system [Dorner et al. Phys. Rev. Lett. 110 230601 (2013)] and [Mazzola et al. Phys. Rev. Lett. 110 230602 (2013)]. The advantage ... More
An introduction to operational quantum dynamicsAug 02 2017In the summer of 2016, physicists gathered in Torun, Poland for the 48th annual Symposium on Mathematical Physics. This Symposium was special; it celebrated the 40th anniversary of the discovery of the Gorini-Kossakowski-Sudarshan-Lindblad master equation, ... More
Kolmogorov extension theorem for general (quantum) stochastic processesDec 07 2017In classical physics, the Kolmogorov extension theorem provides the foundation for the definition and investigation of stochastic processes. In its original form, it does not hold in quantum mechanics. More generally, it does not hold in any theory -- ... More
Non-Markovian quantum control as coherent stochastic trajectoriesFeb 09 2018Feb 12 2018We develop a notion of stochastic quantum trajectories. First, we construct a basis set of trajectories, called elementary trajectories, and go on to show that any quantum dynamical process, including those that are non-Markovian, can be expressed as ... More
How does interference fall?Oct 07 2016We study how single- and double-slit interference patterns fall in the presence of gravity. First, we demonstrate that universality of free fall still holds in this case, i.e., interference patterns fall just like classical objects. Next, we explore lowest ... More
Preparation of states in open quantum mechanicsMar 11 2009Dec 08 2010We study preparation of states for open quantum mechanics. For non-Markovian systems that are initially correlated with the environment, the affects of the preparation procedure are nontrivial. This is due to the indirect affects on the state of the environment ... More
Spookyfying Quantum Information is ImpossibleAug 04 2016Classical information encoded in composite quantum states can be completely hidden from the reduced subsystems and may be found only in the correlations. Can the same be true for quantum information? If quantum information is hidden from subsystems and ... More
Unified View of Quantum and Classical CorrelationsNov 29 2009Mar 03 2010We discuss the problem of the separation of total correlations in a given quantum state into entanglement, dissonance, and classical correlations using the concept of relative entropy as a distance measure of correlations. This allows us to put all correlations ... More
Fragile states are better for quantum metrologyAug 04 2016In quantum metrology, quantum probe states are capable of estimating unknown physical parameters to precisions beyond classical limits. What qualities do such states possess? Here we relate the performance of a probe state at estimating a parameter $\phi$ ... More
Role of correlations in the two-body-marginal problemOct 03 2013Oct 14 2014Quantum properties of correlations have a key role in disparate fields of physics, from quantum information processing, to quantum foundations, to strongly correlated systems. We tackle a specific aspect of the fundamental quantum marginal problem: we ... More
Detecting Multipartite Classical States and their ResemblancesMay 24 2010Sep 24 2010We study various types of multipartite states lying near the quantum-classical boundary. The class of so-called classical states are precisely those in which each party can perform a projective measurement to identify a locally held state without disturbing ... More
Positivity in the presence of initial system-environment correlationMar 23 2012Dec 15 2012The constraints imposed by the initial system-environment correlation can lead to nonpositive Dynamical maps. We find the conditions for positivity and complete positivity of such dynamical maps by using the concept of an assignment map. Any initial system-environment ... More
Quantum thermodynamics of general quantum processesJun 11 2014Mar 27 2015Accurately describing work extraction from a quantum system is a central objective for the extension of thermodynamics to individual quantum systems. The concepts of work and heat are surprisingly subtle when generalizations are made to arbitrary quantum ... More
Completely Positive Maps and Classical CorrelationsMar 02 2007Oct 29 2009We expand the set of initial states of a system and its environment that are known to guarantee completely positive reduced dynamics for the system when the combined state evolves unitarily. We characterize the correlations in the initial state in terms ... More
Coherent and incoherent contents of correlationsFeb 04 2009Aug 08 2012We examine bipartite and multipartite correlations within the construct of unitary orbits. We show that the set of product states is a very small subset of set of all possible states, while all unitary orbits contain classically correlated states. Using ... More
Operational Markov condition for quantum processesJan 30 2018We derive a necessary and sufficient condition for a quantum process to be Markovian which coincides with the classical one in the relevant limit. Our condition unifies all previously known definitions for quantum Markov processes by accounting for all ... More
The power of one qumode for quantum computationOct 16 2015May 03 2016Although quantum computers are capable of solving problems like factoring exponentially faster than the best-known classical algorithms, determining the resources responsible for their computational power remains unclear. An important class of problems ... More
Entanglement, non-Markovianity, and causal non-separabilityNov 11 2017Quantum mechanics, in principle, allows for processes with indefinite causal order. However, most of these causal anomalies have not yet been detected experimentally. We show that every such process can be simulated experimentally by means of non-Markovian ... More
Complete framework for efficient characterisation of non-Markovian processesDec 02 2015Oct 18 2016A non-Markovian process is one that retains 'memory' of its past. A systematic understanding of these processes is necessary to fully describe and harness a vast range of complex phenomena; however, no such general characterisation currently exists. This ... More
Divisible quantum dynamics satisfies temporal Tsirelson's boundOct 15 2015We show that divisibility of qubit quantum processes implies temporal Tsirelson's bound. We also prove that the classical bound of the temporal Bell's inequality holds for dynamics that can be described by entanglement-breaking channels---a more general ... More
Excessive distribution of quantum entanglementJun 05 2015Jun 09 2015We classify protocols of entanglement distribution as excessive and non-excessive ones. In a non-excessive protocol, the gain of entanglement is bounded by the amount of entanglement being communicated between the remote parties, while excessive protocols ... More
Power of One Bit of Quantum Information in Quantum MetrologyApr 09 2015Apr 10 2015We construct a model of quantum metrology inspired by the computational model known as deterministic quantum computation with one quantum bit (DQC1). Using only one pure qubit together with $l$ fully-mixed qubits we obtain measurement precision at the ... More
A non-equilibrium quantum Landauer principleFeb 18 2014Jan 09 2015Using the operational framework of completely positive, trace preserving operations and thermodynamic fluctuation relations, we derive a lower bound for the heat exchange in a Landauer erasure process on a quantum system. Our bound comes from a non-phenomenological ... More
Reconstructing open quantum system dynamics with limited controlOct 07 2016The dynamics of an open quantum system can be fully described and tomographically reconstructed if the experimenter has complete control over the system of interest. Most real-world experiments do not fulfill this assumption, and the amount of control ... More
Emergence of a fluctuation relation for heat in typical open quantum processesOct 28 2015In a generalisation of the Landauer erasure protocol, we study bounds on the heat generated in typical open quantum processes. We derive a fluctuation relation for this heat, implying that it is almost always positive when either the system or reservoir ... More
The relation between nonlocality and contextuality for a biphotonJul 09 2012Feb 26 2013We investigate the set of qutrit states in terms of symmetric states of two qubits that violate the minimal contextual inequality, namely the Klyachko-Can-Binicoglu-Shumovsky (KCBS) inequality. The physical system that provides a natural framework for ... More
Linear Assignment Maps for Correlated System-Environment StatesOct 29 2009Dec 18 2009An assignment map is a mathematical operator that describes initial system-environment states for open quantum systems. We reexamine the notion of assignments, introduced by Pechukas, and show the conditions assignments can account for correlations between ... More
Supersensitive measurement using single-atom control of an atomic ensembleNov 09 2015We analyze the operation of a novel sensor based on atom interferometry, which can achieve supra-classical sensitivity by exploiting quantum correlations in mixed states of many qubits. The interferometer is based on quantum gates which use coherently-controlled ... More
Quantum Correlations in Mixed-State MetrologyMar 05 2010Dec 30 2011We analyze the effects of quantum correlations, such as entanglement and discord, on the efficiency of phase estimation by studying four quantum circuits that can be readily implemented using NMR techniques. These circuits define a standard strategy of ... More
Dynamical role of system-environment correlations in non-Markovian dynamicsMar 16 2012Jul 31 2012We analyse the role played by system-environment correlations in the emergence of non-Markovian dynamics. By working within the framework developed in Breuer et al., Phys. Rev. Lett. 103, 210401 (2009), we unveil a fundamental connection between non-Markovian ... More
Measuring quantumness via anticommutatorsJan 05 2012May 27 2013We introduce a method to witness the quantumness of a system. The method relies on the fact that the anticommutator of two classical states is always positive. We show that there is always a nonpositive anticommutator due to any two quantum states. We ... More
Using a biased qubit to probe complex systemsJul 17 2015Sep 15 2016Complex mesoscopic systems play increasingly important roles in modern science -- from understanding biological functions at the molecular level, to designing solid-state information processing devices. The operation of these systems typically depends ... More
Classical to quantum in large number limitDec 26 2011Mar 28 2012We construct a quantumness witness following the work of Alicki and van Ryn (AvR) in "A simple test of quantumness for a single system" [J. Phys. A: Math. Theor., vol. 41, 062001 (2008)]. The AvR test is designed to detect quantumness. We reformulate ... More
Quantacell: Powerful charging of quantum batteriesMar 24 2015Jul 27 2015We study the problem of charging a quantum battery in finite time. We demonstrate an analytical optimal protocol for the case of a single qubit. Extending this analysis to an array of N qubits, we demonstrate that an N-fold advantage in power per qubit ... More
Quantum Computing with black-box SubroutinesOct 10 2013Nov 21 2013Modern programming relies on our ability to treat preprogrammed functions as black boxes - we can invoke them as subroutines without knowing their physical implementation. Here we show it is generally impossible to execute an unknown quantum subroutine. ... More
The classical-quantum boundary for correlations: discord and related measuresDec 29 2011Nov 27 2012One of the best signatures of nonclassicality in a quantum system is the existence of correlations that have no classical counterpart. Different methods for quantifying the quantum and classical parts of correlations are amongst the more actively-studied ... More
Vanishing quantum discord is not necessary for completely-positive mapsDec 18 2012Apr 04 2013The description of the dynamics of a system that may be correlated with its environment is only meaningful within the context of a specific framework. Different frameworks rely upon different assumptions about the initial system-environment state. We ... More
A fast algorithm for identifying Friends-of-Friends halosJul 12 2016We describe a simple and fast algorithm for identifying friends-of-friends clusters and prove its correctness. The algorithm avoids unnecessary expensive neighbor queries, uses minimal memory overhead, and rejects slowdown in high over-density regions. ... More
A Simple Test of the Equivalence Principle(s) for Quantum SuperpositionsNov 10 2015We propose a simple experimental test of the quantum equivalence principle introduced by Zych and Brukner [arXiv:1502.00971], which generalises the Einstein equivalence principle to superpositions of internal energy states. We consider a harmonically-trapped ... More
Unification of witnessing initial system-environment correlations and witnessing non-MarkovianityApr 10 2012We show the connection between a witness that detects dynamical maps with initial system-environment correlations and a witness that detects non-Markovian open quantum systems. Our analysis is based on studying the role that state preparation plays in ... More
How state preparation can affect a quantum experiment: Quantum process tomography for open systemsJun 04 2007Oct 29 2009We study the effects of preparation of input states in a quantum tomography experiment. We show that maps arising from a quantum process tomography experiment (called process maps) differ from the well know dynamical maps. The difference between the two ... More
Characterizing quantum dynamics with initial system-environment correlationsOct 21 2014We fully characterize the reduced dynamics of an open quantum system initially correlated with its environment. Using a photonic qubit coupled to a simulated environment we tomographically reconstruct a superchannel---a generalised channel that treats ... More
Quantum thermodynamics for a model of an expanding universeSep 18 2014Jan 12 2016We investigate the thermodynamical properties of quantum fields in curved spacetime. Our approach is to consider quantum fields in curved spacetime as a quantum system undergoing an out-of-equilibrium transformation. The non-equilibrium features are studied ... More
Local random potentials of high differentiability to model the LandscapeSep 17 2014Mar 10 2015We generate random functions locally via a novel generalization of Dyson Brownian motion, such that the functions are in a desired differentiability class, while ensuring that the Hessian is a member of the Gaussian orthogonal ensemble (other ensembles ... More
Operational Significance of Discord Consumption: Theory and ExperimentFeb 29 2012Aug 04 2012Coherent interactions that generate negligible entanglement can still exhibit unique quantum behaviour. This observation has motivated a search beyond entanglement for a complete description of all quantum correlations. Quantum discord is a promising ... More
Image Processing based Systems and Techniques for the Recognition of Ancient and Modern CoinsDec 23 2013Coins are frequently used in everyday life at various places like in banks, grocery stores, supermarkets, automated weighing machines, vending machines etc. So, there is a basic need to automate the counting and sorting of coins. For this machines need ... More
Automated Coin Recognition System using ANNDec 23 2013Coins are integral part of our day to day life. We use coins everywhere like grocery store, banks, buses, trains etc. So it becomes a basic need that coins can be sorted and counted automatically. For this it is necessary that coins can be recognized ... More
Towards Real-time Simulation of Hyperelastic MaterialsApr 25 2016We present a new method for real-time physics-based simulation supporting many different types of hyperelastic materials. Previous methods such as Position Based or Projective Dynamics are fast, but support only limited selection of materials; even classical ... More
Experimental demonstration of information to energy conversion in a quantum system at the Landauer LimitDec 19 2014Mar 14 2016Landauer's principle sets fundamental thermodynamical constraints for classical and quantum information processing, thus affecting not only various branches of physics, but also of computer science and engineering. Despite its importance, this principle ... More
Estimates for solutions of the $\partial$-equation and application to the characterization of the zero varieties of the functions of the nevanlinna class for lineally convex domains of finite typeFeb 07 2011Feb 19 2013In the late ten years, the resolution of the equation $\bar\partial u=f$ with sharp estimates has been intensively studied for convex domains of finite type by many authors. In this paper, we consider the case of lineally convex domains. As the method ... More
Halo bias in Lagrangian Space: Estimators and theoretical predictionsDec 06 2016We present several methods to accurately estimate Lagrangian bias parameters, in particular the quadratic terms, both the local and the non local ones and show the first clear evidence for the latter. Using Fourier space correlations, we also show for ... More
Estimates for some Weighted Bergman ProjectionsDec 05 2012May 23 2013In this paper we investigate the regularity properties of weighted Bergman projections for smoothly bounded pseudo-convex domains of finite type in $\mathbb{C}^{n}$. The main result is obtained for weights equal to a non negative rational power of the ... More
On estimates for weighted Bergman projectionsMar 13 2014Apr 04 2014In this note we show that the weighted $L^{2}$-Sobolev estimates obtained by P. Charpentier, Y. Dupain & M. Mounkaila for the weighted Bergman projection of the Hilbert space $L^{2}\left(\Omega,d\mu_{0}\right)$ where $\Omega$ is a smoothly bounded pseudoconvex ... More
Interaction between graphene and copper substrate: The role of lattice orientationJan 31 2014We present a comprehensive study of graphene grown by chemical vapor deposition on copper single crystals with exposed (100), (110) and (111) faces. Direct examination of the as-grown graphene by Raman spectroscopy using a range of visible excitation ... More
A Measurement of the Cosmological Constant Using Elliptical Galaxies as Strong Gravitational LensesNov 13 1996We have identified seven (field) elliptical galaxies acting as strong gravitational lenses and have used them to measure cosmological parameters. To find the most likely value for Omega_m (= Omega_matter) and Lambda, we have used the combined probabilities ... More
Cosmic Gravitational Shear from the HST Medium Deep SurveyNov 13 2003We present a measurement of cosmic shear on scales ranging from $ 10\arcsec $ to $ 2\arcmin $ in 347 WFPC2 images of random fields. Our result is based on shapes measured via image fitting and on a simple statistical technique; careful calibration of ... More
A novel approach for e-payment using virtual password systemAug 19 2012In today's world of E-Commerce everything comes online like Music, E-Books, Shopping all most everything is online. If you are using some service or buying things online then you have to pay for that. For that you have to do Net Banking or you have to ... More
Quantum locking of classical correlations and quantum discord of classical-quantum statesMay 13 2011May 16 2011A locking protocol between two parties is as follows: Alice gives an encrypted classical message to Bob which she does not want Bob to be able to read until she gives him the key. If Alice is using classical resources, and she wants to approach unconditional ... More
Consistently Orienting Facets in Polygon Meshes by Minimizing the Dirichlet Energy of Generalized Winding NumbersJun 20 2014Jun 23 2014Jacobson et al. [JKSH13] hypothesized that the local coherency of the generalized winding number function could be used to correctly determine consistent facet orientations in polygon meshes. We report on an approach to consistently orienting facets in ... More
Investigation of Gravitational Lens Mass ModelsApr 06 2001We have previously reported the discovery of strong gravitational lensing by faint elliptical galaxies using the WFPC2 on HST and here we investigate their potential usefulness in putting constraints on lens mass models. We compare various ellipsoidal ... More
Disk and Bulge Morphology of WFPC2 galaxies: The HST Medium Deep Survey databaseApr 13 1999Quantitative morphological and structural parameters are estimated for galaxies detected in HST observations of WFPC2 survey fields. A modeling approach based on maximum likelihood has been developed for two-dimensional decomposition of faint under-sampled ... More
The Pattern of CN, O, and Na Inhomogeneities on the Red Giant Branch of Messier 5Oct 18 2013Data from the literature are used to explore the relation between $\lambda$3883 CN band strength and the sodium and oxygen abundances of red giants in the globular cluster Messier 5. Although there is a broad tendency for CN-strong giants in this cluster ... More
InScript: Narrative texts annotated with script informationMar 15 2017This paper presents the InScript corpus (Narrative Texts Instantiating Script structure). InScript is a corpus of 1,000 stories centered around 10 different scenarios. Verbs and noun phrases are annotated with event and participant types, respectively. ... More
On the rupture of DNA moleculeJul 01 2015Using Langevin Dynamic simulations, we study effects of the shear force on the rupture of a double stranded DNA molecule. The model studied here contains two single diblock copolymers interacting with each other. The elastic constants of individual segments ... More
Compact Nuclei in Galaxies at Moderate Redshift:II. Their Nature and Implications for the AGN Luminosity FunctionNov 19 1998This study explores the space density and properties of active galaxies to z=0.8. We have investigated the frequency and nature of unresolved nuclei in galaxies at moderate redshift as indicators of nuclear activity such as Active Galactic Nuclei (AGN) ... More
New "Einstein Cross" Gravitational Lens Candidates in HST WFPC2 Survey ImagesAug 28 1995We report the serendipitous discovery of ``Einstein cross'' gravitational lens candidates using the Hubble Space Telescope. We have so far discovered two good examples of such lenses, each in the form of four faint blue images located in a symmetric configuration ... More
Compact Nuclei in Moderately Redshifted GalaxiesAug 28 1996The Hubble Space Telescope WFPC2 is being used to obtain high-resolution images in the V and I bands for several thousand distant galaxies as part of the Medium Deep Survey (MDS). An important scientific aim of the MDS is to identify possible AGN candidates ... More
Operational interpretations of quantum discordAug 19 2010Apr 01 2011Quantum discord quantifies non-classical correlations going beyond the standard classification of quantum states into entangled and unentangled ones. Although it has received considerable attention, it still lacks any precise interpretation in terms of ... More
A Large-scale Analysis of the Marketplace Characteristics in FiverrSep 20 2016Crowdsourcing platforms have become quite popular due to the increasing demand of human computation-based tasks. Though the crowdsourcing systems are primarily demand-driven like MTurk, supply-driven marketplaces are becoming increasingly popular. Fiverr ... More
Compact Nuclei in Galaxies at Moderate Redshift: I. Imaging and SpectroscopyNov 19 1998This study explores the space density and properties of active galaxies to z=0.8. We have investigated the frequency and nature of unresolved nuclei in galaxies at moderate redshift as indicators of nuclear activity such as Active Galactic Nuclei (AGN) ... More
Luminosity Functions of Elliptical Galaxies at z < 1.2Feb 08 1996The luminosity functions of E/S0 galaxies are constructed in 3 different redshift bins (0.2 < z < 0.55, 0.55 < z < 0.8, 0.8 < z < 1.2), using the data from the Hubble Space Telescope Medium Deep Survey (HST MDS) and other HST surveys. These independent ... More
A Spatial Simulation Approach to Account for Protein Structure When Identifying Non-Random Somatic MutationsOct 27 2013Oct 29 2013Background: Current research suggests that a small set of "driver" mutations are responsible for tumorigenesis while a larger body of "passenger" mutations occurs in the tumor but does not progress the disease. Due to recent pharmacological successes ... More
Work and Quantum Phase Transitions: Is there Quantum Latency?Jul 21 2013May 23 2014We study the physics of quantum phase transitions from the perspective of non-equilibrium thermodynamics. For first order quantum phase transitions, we find that the average work done per quench in crossing the critical point is discontinuous. This leads ... More
Statistical Mechanics of DNA Rupture: Theory and SimulationsOct 05 2013Oct 08 2013We study the effects of the shear force on the rupture mechanism on a double stranded DNA. Motivated by recent experiments, we perform the atomistic simulations with explicit solvent to obtain the distributions of extension in hydrogen and covalent bonds ... More
Completing electron scattering studies with the inert gas column:e - Rn scattering and IonizationFeb 05 2016Interest in the inert or noble- gas atoms in general arises because they are ideal as test systems for various theoretical models of electron scattering and also since their interaction processes serve as reference for the determination of instrumental ... More
Utilizing Protein Structure to Identify Non-Random Somatic MutationsFeb 27 2013Motivation: Human cancer is caused by the accumulation of somatic mutations in tumor suppressors and oncogenes within the genome. In the case of oncogenes, recent theory suggests that there are only a few key "driver" mutations responsible for tumorigenesis. ... More
Coherent measurements in quantum metrologySep 12 2012Feb 19 2015It is well known that a quantum correlated probe can yield better precision in estimating an unknown parameter than classically possible. However, how such a quantum probe should be measured remains somewhat elusive. We examine the role of measurements ... More
A Graph Theoretic Approach to Utilizing Protein Structure to Identify Non-Random Somatic MutationsMar 23 2013Jul 12 2013Background: It is well known that the development of cancer is caused by the accumulation of somatic mutations within the genome. For oncogenes specifically, current research suggests that there is a small set of "driver" mutations that are primarily ... More
Quantum discord bounds the amount of distributed entanglementMar 06 2012Jul 31 2012The ability to distribute quantum entanglement is a prerequisite for many fundamental tests of quantum theory and numerous quantum information protocols. Two distant parties can increase the amount of entanglement between them by means of quantum communication ... More
nbodykit: an open-source, massively parallel toolkit for large-scale structureDec 15 2017We present nbodykit, an open-source, massively parallel Python toolkit for analyzing large-scale structure (LSS) data. Using Python bindings of the Message Passing Interface (MPI), we provide parallel implementations of many commonly used algorithms in ... More
The morphological mix of field galaxies to I=24.25 magnitudes (b=26 magnitudes) from a deep Hubble Space Telescope WFPC2 imageNov 28 1995We determine the morphological mix of field galaxies down to $m_{I}\simeq 24.25$ mag ($m_{B}\sim 26.0$ mag) from a single ultradeep HST WFPC2 image in both the $V_{606}$ and $I_{814}$ filters. In total, we find 227 objects with $m_{I}\le 24.5$ mag and ... More
Phonon and structural changes in deformed Bernal stacked bilayer grapheneFeb 08 2012We present the first Raman spectroscopic study of Bernal bilayer graphene flakes under uniaxial tension. Apart from a purely mechanical behavior in flake regions where both layers are strained evenly, certain effects stem from inhomogeneous stress distribution ... More
Raman 2D-Band Splitting in Graphene: Theory and ExperimentMar 24 2011We present a systematic experimental and theoretical study of the two-phonon (2D) Raman scattering in graphene under uniaxial tension. The external perturbation unveils that the 2D mode excited with 785nm has a complex line-shape mainly due to the contribution ... More
Surface and interface study of pulsed-laser-deposited off-stoichiometric NiMnSb thin films on Si(100) substrateOct 13 2005We report a detailed study of surface and interface properties of pulsed-laser deposited NiMnSb films on Si (100) substrate as a function of film thickness. As the thickness of films is reduced below 35 nm formation of a porous layer is observed. Porosity ... More
The RoboPol optical polarization survey of gamma-ray - loud blazarsNov 13 2013May 15 2014We present first results from RoboPol, a novel-design optical polarimeter operating at the Skinakas Observatory in Crete. The data, taken during the May - June 2013 commissioning of the instrument, constitute a single-epoch linear polarization survey ... More
RoboPol: First season rotations of optical polarization plane in blazarsMay 27 2015Mar 22 2016We present first results on polarization swings in optical emission of blazars obtained by RoboPol, a monitoring program of an unbiased sample of gamma-ray bright blazars specially designed for effective detection of such events. A possible connection ... More
Early-time polarized optical light curve of GRB 131030ASep 08 2014Sep 10 2014We report the polarized optical light curve of a gamma-ray burst afterglow obtained using the RoboPol instrument. Observations began 655 seconds after the initial burst of gamma-rays from GRB131030A, and continued uninterrupted for 2 hours. The afterglow ... More
The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Anisotropic galaxy clustering in Fourier-spaceJul 11 2016We investigate the anisotropic clustering of the Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12 (DR12) sample, which consists of $1\,198\,006$ galaxies in the redshift range $0.2 < z < 0.75$ and a sky coverage of $10\,252\,$deg$^2$. We ... More
RoboPol: optical polarization-plane rotations and flaring activity in blazarsJan 13 2016Jan 15 2016We present measurements of rotations of the optical polarization of blazars during the second year of operation of RoboPol, a monitoring programme of an unbiased sample of gamma-ray bright blazars specially designed for effective detection of such events, ... More
The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Baryon Acoustic Oscillations in Fourier-spaceJul 11 2016We analyse the Baryon Acoustic Oscillation (BAO) signal of the final Baryon Oscillation Spectroscopic Survey (BOSS) data release (DR12). Our analysis is performed in Fourier-space, using the power spectrum monopole and quadrupole. The dataset includes ... More