Results for "L. DiCarlo"

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Digital feedback in superconducting quantum circuitsAug 06 2015This chapter covers the development of feedback control of superconducting qubits using projective measurement and a discrete set of conditional actions, here referred to as digital feedback. We begin with an overview of the applications of digital feedback ... More
General method for extracting the quantum efficiency of dispersive qubit readout in circuit QEDNov 14 2017Apr 05 2018We present and demonstrate a general three-step method for extracting the quantum efficiency of dispersive qubit readout in circuit QED. We use active depletion of post-measurement photons and optimal integration weight functions on two quadratures to ... More
Time-domain characterization and correction of on-chip distortion of control pulses in a quantum processorJul 10 2019We introduce Cryoscope, a method for sampling on-chip baseband pulses used to dynamically control qubit frequency in a quantum processor. We specifically use Cryoscope to measure the step response of the dedicated flux control lines of two-junction transmon ... More
Phenomenology of the 0.7 conductance featureJan 07 2006We describe a phenomenological model for the conductance feature near $0.7 \times 2e^2/h$ that occurs in quantum point contacts. We focus on the transconductance at finite source-drain bias and contrast our model with the results expected from a single-particle ... More
Quantum Hall Effect in a Graphene p-n JunctionApr 26 2007Aug 28 2007We report on the fabrication and transport studies of a single-layer graphene p-n junction. Carrier type and density in two adjacent regions are individually controlled by electrostatic gating using a local top gate and a global back gate. A functionalized ... More
Density-matrix simulation of small surface codes under current and projected experimental noiseMar 12 2017Jan 08 2018We present a full density-matrix simulation of the quantum memory and computing performance of the distance-3 logical qubit Surface-17, following a recently proposed quantum circuit and using experimental error parameters for transmon qubits in a planar ... More
Feedback control of a solid-state qubit using high-fidelity projective measurementJul 12 2012We demonstrate feedback control of a superconducting transmon qubit using discrete, projective measurement and conditional coherent driving. Feedback realizes a fast and deterministic qubit reset to a target state with 2.4% error averaged over input superposition ... More
Mitigating information leakage in a crowded spectrum of weakly anharmonic qubitsMay 02 2014May 11 2014A challenge for scaling up quantum processors using frequency-crowded, weakly anharmonic qubits is to drive individual qubits without causing leakage into non-computational levels of the others, while also minimizing the number of control lines. To address ... More
Error Mitigation by Symmetry Verification on a Variational Quantum EigensolverFeb 28 2019Variational quantum eigensolvers offer a small-scale testbed to demonstrate the performance of error mitigation techniques with low experimental overhead. We present successful error mitigation by applying the recently proposed symmetry verification technique ... More
Photovoltaic and Rectification Currents in Quantum DotsOct 02 2004We investigate theoretically and experimentally the statistical properties of dc current through an open quantum dot subject to ac excitation of a shape-defining gate. The symmetries of rectification current and photovoltaic current with respect to applied ... More
Photocurrent, Rectification, and Magnetic Field Symmetry of Induced Current Through Quantum DotsApr 17 2003We report mesoscopic dc current generation in an open chaotic quantum dot with ac excitation applied to one of the shape-defining gates. For excitation frequencies large compared to the inverse dwell time of electrons in the dot (i.e., GHz), we find mesoscopic ... More
A system for measuring auto- and cross-correlation of current noise at low temperaturesApr 02 2006Jun 09 2006We describe the construction and operation of a two-channel noise detection system for measuring power and cross spectral densities of current fluctuations near 2 MHz in electronic devices at low temperatures. The system employs cryogenic amplification ... More
Quantum Hall conductance of two-terminal graphene devicesOct 20 2008Measurement and theory of the two-terminal conductance of monolayer and bilayer graphene in the quantum Hall regime are compared. We examine features of conductance as a function of gate voltage that allow monolayer, bilayer, and gapped samples to be ... More
Digital Quantum Rabi and Dicke Models in Superconducting CircuitsMay 22 2014Dec 15 2014We propose the analog-digital quantum simulation of the quantum Rabi and Dicke models using circuit quantum electrodynamics (QED). We find that all physical regimes, in particular those which are impossible to realize in typical cavity QED setups, can ... More
Entanglement genesis by ancilla-based parity measurement in 2D circuit QEDNov 21 2013We present an indirect two-qubit parity meter in planar circuit quantum electrodynamics, realized by discrete interaction with an ancilla and a subsequent projective ancilla measurement with a dedicated, dispersively coupled resonator. Quantum process ... More
Detecting bit-flip errors in a logical qubit using stabilizer measurementsNov 20 2014Quantum data is susceptible to decoherence induced by the environment and to errors in the hardware processing it. A future fault-tolerant quantum computer will use quantum error correction (QEC) to actively protect against both. In the smallest QEC codes, ... More
Zero-field splitting of Kondo resonances in a carbon nanotube quantum dotOct 19 2004Oct 25 2004We present low-temperature electron transport measurements on a single-wall carbon nanotube quantum dot exhibiting Kondo resonances at low temperature. Contrary to the usual behavior for the spin-1/2 Kondo effect we find that the temperature dependence ... More
Millisecond charge-parity fluctuations and induced decoherence in a superconducting qubitDec 21 2012Quasiparticle excitations adversely affect the performance of superconducting devices in a wide range of applications. They limit the sensitivity of photon detectors in astronomy, the accuracy of current sources in metrology, the cooling power of micro-refrigerators, ... More
Shot Noise in GrapheneNov 20 2007Feb 21 2008We report measurements of current noise in single- and multi-layer graphene devices. In four single-layer devices, including a p-n junction, the Fano factor remains constant to within +/-10% upon varying carrier type and density, and averages between ... More
Initialization by measurement of a two-qubit superconducting circuitApr 11 2012We demonstrate initialization by joint measurement of two transmon qubits in 3D circuit quantum electrodynamics. Homodyne detection of cavity transmission is enhanced by Josephson parametric amplification to discriminate the two-qubit ground state from ... More
Realization of Three-Qubit Quantum Error Correction with Superconducting CircuitsSep 22 2011Quantum computers promise to solve certain problems exponentially faster than possible classically but are challenging to build because of their increased susceptibility to errors. Remarkably, however, it is possible to detect and correct errors without ... More
High-Fidelity Readout in Circuit Quantum Electrodynamics Using the Jaynes-Cummings NonlinearityApr 25 2010Oct 19 2010We demonstrate a qubit readout scheme that exploits the Jaynes-Cummings nonlinearity of a superconducting cavity coupled to transmon qubits. We find that in the strongly-driven dispersive regime of this system, there is the unexpected onset of a high-transmission ... More
High Kinetic Inductance Superconducting Nanowire Resonators for Circuit QED in a Magnetic FieldNov 05 2015We present superconducting microwave-frequency resonators based on NbTiN nanowires. The small cross section of the nanowires minimizes vortex generation, making the resonators resilient to magnetic fields. Measured intrinsic quality factors exceed $2\times ... More
Calculating energy derivatives for quantum chemistry on a quantum computerMay 09 2019Jun 17 2019Modeling chemical reactions and complicated molecular systems has been proposed as the `killer application' of a future quantum computer. Accurate calculations of derivatives of molecular eigenenergies are essential towards this end, allowing for geometry ... More
Partial-measurement back-action and non-classical weak values in a superconducting circuitFeb 20 2013We realize indirect partial measurement of a transmon qubit in circuit quantum electrodynamics by interaction with an ancilla qubit and projective ancilla measurement with a dedicated readout resonator. Accurate control of the interaction and ancilla ... More
Independent, extensible control of same-frequency superconducting qubits by selective broadcastingAug 26 2015A critical ingredient for realizing large-scale quantum information processors will be the ability to make economical use of qubit control hardware. We demonstrate an extensible strategy for reusing control hardware on same-frequency transmon qubits in ... More
Selective darkening of degenerate transitions for implementing quantum controlled-NOT gatesJan 16 2012Jul 23 2012We present a theoretical analysis of the selective darkening method for implementing quantum controlled-NOT (CNOT) gates. This method, which we recently proposed and demonstrated, consists of driving two transversely-coupled quantum bits (qubits) with ... More
Chip-to-chip entanglement of transmon qubits using engineered measurement fieldsDec 17 2017While the on-chip processing power in circuit QED devices is growing rapidly, an open challenge is to establish high-fidelity quantum links between qubits on different chips. Here, we show entanglement between transmon qubits on different cQED chips with ... More
Shot-Noise Signatures of 0.7 Structure and Spin in a Quantum Point ContactApr 02 2006Jun 09 2006We report simultaneous measurement of shot noise and dc transport in a quantum point contact as a function of source-drain bias, gate voltage, and in-plane magnetic field. Shot noise at zero field exhibits an asymmetry related to the 0.7 structure in ... More
Implementing optimal control pulse shaping for improved single-qubit gatesMay 07 2010We employ pulse shaping to abate single-qubit gate errors arising from the weak anharmonicity of transmon superconducting qubits. By applying shaped pulses to both quadratures of rotation, a phase error induced by the presence of higher levels is corrected. ... More
Reducing intrinsic loss in superconducting resonators by surface treatment and deep etching of silicon substratesFeb 13 2015We present microwave-frequency NbTiN resonators on silicon, systematically achieving internal quality factors above 1 M in the quantum regime. We use two techniques to reduce losses associated with two-level systems: an additional substrate surface treatment ... More
Calculating energy derivatives for quantum chemistry on a quantum computerMay 09 2019Modeling chemical reactions and complicated molecular systems has been proposed as the `killer application' of a future quantum computer. Accurate calculations of derivatives of molecular eigenenergies are essential towards this end, allowing for geometry ... More
Tunable Noise Cross-Correlations in a Double Quantum DotJul 11 2006We report measurements of the cross-correlation between current noise fluctuations in two capacitively coupled quantum dots in the Coulomb blockade regime. The sign of the cross-spectral density is found to be tunable by gate voltage and source-drain ... More
Task-Driven Convolutional Recurrent Models of the Visual SystemJun 20 2018Oct 27 2018Feed-forward convolutional neural networks (CNNs) are currently state-of-the-art for object classification tasks such as ImageNet. Further, they are quantitatively accurate models of temporally-averaged responses of neurons in the primate brain's visual ... More
Noise Correlations in a Coulomb Blockaded Quantum DotMar 15 2007We report measurements of current noise auto- and cross-correlation in a tunable quantum dot with two or three leads. As the Coulomb blockade is lifted at finite source-drain bias, the auto-correlation evolves from super-Poissonian to sub-Poissonian in ... More
Experimentally simulating the dynamics of quantum light and matter at ultrastrong couplingOct 31 2016The quantum Rabi model describing the fundamental interaction between light and matter is a cornerstone of quantum physics. It predicts exotic phenomena like quantum phase transitions and ground-state entanglement in the ultrastrong-coupling (USC) regime, ... More
Scalable quantum circuit and control for a superconducting surface codeDec 24 2016We present a scalable scheme for executing the error-correction cycle of a monolithic surface-code fabric composed of fast-flux-tuneable transmon qubits with nearest-neighbor coupling. An eight-qubit unit cell forms the basis for repeating both the quantum ... More
High cooperativity coupling of electron-spin ensembles to superconducting cavitiesJun 01 2010Electron spins in solids are promising candidates for quantum memories for superconducting qubits because they can have long coherence times, large collective couplings, and many quantum bits can be encoded into the spin-waves of a single ensemble. We ... More
Preparation and Measurement of Three-Qubit Entanglement in a Superconducting CircuitApr 25 2010Traditionally, quantum entanglement has played a central role in foundational discussions of quantum mechanics. The measurement of correlations between entangled particles can exhibit results at odds with classical behavior. These discrepancies increase ... More
Entanglement Metrology Using a Joint Readout of Superconducting QubitsAug 13 2009Accurate and precise detection of multi-qubit entanglement is key for the experimental development of quantum computation. Traditionally, non-classical correlations between entangled qubits are measured by counting coincidences between single-shot readouts ... More
Current Noise in Quantum Point ContactsApr 30 2007We present measurements of current noise in quantum point contacts as a function of source-drain bias, gate voltage, and in-plane magnetic field. At zero bias, Johnson noise provides a measure of the electron temperature. At finite bias, shot noise at ... More
Reversing quantum trajectories with analog feedbackNov 21 2013We demonstrate the active suppression of transmon qubit dephasing induced by dispersive measurement, using parametric amplification and analog feedback. By real-time processing of the homodyne record, the feedback controller reverts the stochastic quantum ... More
Fast Reset and Suppressing Spontaneous Emission of a Superconducting QubitFeb 28 2010May 31 2010Spontaneous emission through a coupled cavity can be a significant decay channel for qubits in circuit quantum electrodynamics. We present a circuit design that effectively eliminates spontaneous emission due to the Purcell effect while maintaining strong ... More
Realization of microwave quantum circuits using hybrid superconducting-semiconducting nanowire Josephson elementsMar 29 2015We report the realization of quantum microwave circuits using hybrid superconductor-semiconductor Josephson elements comprised of InAs nanowires contacted by NbTiN. Capacitively-shunted single elements behave as transmon qubits with electrically tunable ... More
A fast, low-leakage, high-fidelity two-qubit gate for a programmable superconducting quantum computerMar 06 2019A common approach to realize conditional-phase (CZ) gates in transmon qubits relies on flux control of the qubit frequency to make computational states interact with non-computational ones using a fast-adiabatic trajectory to minimize leakage. We develop ... More
Evolution of Nanowire Transmons and Their Quantum Coherence in Magnetic FieldNov 21 2017We present an experimental study of nanowire transmons at zero and applied in-plane magnetic field. With Josephson non-linearities provided by the nanowires, our qubits operate at higher magnetic fields than standard transmons. Nanowire transmons exhibit ... More
Differential Charge Sensing and Charge Delocalization in a Tunable Double Quantum DotNov 13 2003Feb 07 2004We report measurements of a tunable double quantum dot, operating in the quantum regime, with integrated local charge sensors. The spatial resolution of the sensors is sufficient to allow the charge distribution within the double dot system to be resolved ... More
Probing dynamics of an electron-spin ensemble via a superconducting resonatorAug 27 2012We study spin relaxation and diffusion in an electron-spin ensemble of nitrogen impurities in diamond at low temperature (0.25-1.2 K) and polarizing magnetic field (80-300 mT). Measurements exploit mode- and temperature-dependent coupling of hyperfine-split ... More
Deep Neural Networks Rival the Representation of Primate IT Cortex for Core Visual Object RecognitionJun 12 2014The primate visual system achieves remarkable visual object recognition performance even in brief presentations and under changes to object exemplar, geometric transformations, and background variation (a.k.a. core visual object recognition). This remarkable ... More
Deterministic entanglement of superconducting qubits by parity measurement and feedbackJun 17 2013The stochastic evolution of quantum systems during measurement is arguably the most enigmatic feature of quantum mechanics. Measuring a quantum system typically steers it towards a classical state, destroying any initial quantum superposition and any ... More
Teacher Guided Architecture SearchAug 04 2018Strong improvements in network performance in vision tasks have resulted from the search of alternative network architectures, and prior work has shown that this search process can be automated and guided by evaluating candidate network performance following ... More
Teacher Guided Architecture SearchAug 04 2018Apr 19 2019Much of the recent improvements in computer vision models has resulted from discovery of new network architectures. To reduce the computational cost of searching through possible architectures, most prior work has used the performance of candidate models ... More
Measurements of Quasiparticle Tunneling Dynamics in a Bandgap-Engineered Transmon QubitDec 12 2011We have engineered the bandgap profile of transmon qubits by combining oxygen-doped Al for tunnel junction electrodes and clean Al as quasiparticle traps to investigate energy relaxation due to quasiparticle tunneling. The relaxation time $T_1$ of the ... More
Quantum Non-demolition Detection of Single Microwave Photons in a CircuitMar 13 2010Thorough control of quantum measurement is key to the development of quantum information technologies. Many measurements are destructive, removing more information from the system than they obtain. Quantum non-demolition (QND) measurements allow repeated ... More
An Experimental Microarchitecture for a Superconducting Quantum ProcessorAug 25 2017Quantum computers promise to solve certain problems that are intractable for classical computers, such as factoring large numbers and simulating quantum systems. To date, research in quantum computer engineering has focused primarily at opposite ends ... More
Active resonator reset in the nonlinear dispersive regime of circuit QEDApr 04 2016Jun 27 2016We present two pulse schemes for actively depleting measurement photons from a readout resonator in the nonlinear dispersive regime of circuit QED. One method uses digital feedback conditioned on the measurement outcome while the other is unconditional. ... More
Liquid relaxation: A new Parodi-like relation for nematic liquid crystalsSep 30 2015Jun 10 2016We put forward a hydrodynamic theory of nematic liquid crystals that includes both anisotropic elasticity and dynamic relaxation. Liquid remodeling is encompassed through a continuous update of the shear-stress free configuration. The low-frequency limit ... More
Design of nanoparticles for generation and stabilization of CO2-in-brine foams with or without added surfactantsNov 27 2018Whereas many studies have examined stabilization of emulsions and foams in low salinity aqueous phases with nanoparticles (NPs) with and without added surfactants, interest has grown recently in much higher salinities relevant to subsurface oil and gas ... More
Protecting quantum entanglement from qubit errors and leakage via repetitive parity measurementsMay 29 2019Protecting quantum information from errors is essential for large-scale quantum computation. Quantum error correction (QEC) encodes information in entangled states of many qubits, and performs parity measurements to identify errors without destroying ... More
Demonstration of Two-Qubit Algorithms with a Superconducting Quantum ProcessorMar 11 2009May 04 2009By harnessing the superposition and entanglement of physical states, quantum computers could outperform their classical counterparts in solving problems of technological impact, such as factoring large numbers and searching databases. A quantum processor ... More
Design of nanoparticles for generation and stabilization of CO2-in-brine foams with or without added surfactantsNov 27 2018May 30 2019Whereas many studies have examined stabilization of emulsions and foams in low salinity aqueous phases with nanoparticles (NPs) with and without added surfactants, interest has grown recently in much higher salinities relevant to subsurface oil and gas ... More
eQASM: An Executable Quantum Instruction Set ArchitectureAug 07 2018Mar 09 2019A widely-used quantum programming paradigm comprises of both the data flow and control flow. Existing quantum hardware cannot well support the control flow, significantly limiting the range of quantum software executable on the hardware. By analyzing ... More
Restless Tuneup of High-Fidelity Qubit GatesNov 15 2016We present a tuneup protocol for qubit gates with tenfold speedup over traditional methods reliant on qubit initialization by energy relaxation. This speedup is achieved by constructing a cost function for Nelder-Mead optimization from real-time correlation ... More
Deep brain fluorescence imaging with minimally invasive ultra-thin optical fibersMar 03 2017Nov 09 2017A major open challenge in neuroscience is the ability to measure and perturb neural activity in vivo from well-defined neural sub-populations at cellular resolution anywhere in the brain. However, limitations posed by scattering and absorption prohibit ... More
Effects of macroscopic-polarization built-in electrostatic fields in III-V nitrides multi-quantum-wellsAug 10 1998Jan 20 1999Huge built-in electric fields have been predicted to exist in wurtzite III-V nitrides thin films and multilayers. Such fields originate from heterointerface discontinuities of the macroscopic bulk polarization of the nitrides. Here we discuss the background ... More
Fermionic effective action and the pahse estructure of non compact quantum electrodynamics in 2+1 dimensionsMay 20 1993We study the phase diagram of non compact $QED_3$ using the microcanonical fermionic average method described elsewhere. We present evidence for a continuous phase transition line in the $\beta, N$ plane, extending down to arbitrarily small flavour number ... More
The Neural Representation Benchmark and its Evaluation on Brain and MachineJan 15 2013Jan 25 2013A key requirement for the development of effective learning representations is their evaluation and comparison to representations we know to be effective. In natural sensory domains, the community has viewed the brain as a source of inspiration and as ... More
Measurement of Branching Fractions of Hadronic Decays of the $Ω_c^0$ BaryonDec 04 2017Jan 17 2018Using a data sample of 980 ${\rm fb}^{-1}$ of $e^+e^-$ annihilation data taken with the Belle detector operating at the KEKB asymmetric-energy $e^+e^-$ collider, we report the results of a study of the decays of the $\Omega_c^0$ charmed baryon into hadronic ... More
Classification of 6-dimensional real Drinfeld doublesFeb 21 2002Mar 27 2002Starting from the classification of real Manin triples done in a previous paper we look for those that are isomorphic as 6-dimensional Lie algebras with the ad-invariant form used for construction of the Manin triples. We use several invariants of the ... More
Poisson-Lie T-plurality of three-dimensional conformally invariant sigma modelsMar 16 2004May 18 2004Starting from the classification of 6-dimensional Drinfeld doubles and their decomposition into Manin triples we construct 3-dimensional Poisson-Lie T-dual or more precisely T-plural sigma models. Of special interest are those that are conformally invariant. ... More
Reply to Comment on "Statistical mechanics of developable ribbons"Nov 09 2011Starostin and van der Heijden [arXiv:1111.2029] question the validity of the results reported in our Letter [Phys. Rev. Lett. 104, 238104 (2010)] regarding the existence of spontaneous helical structure in finite-temperature developable ribbons. According ... More
Multistability of free spontaneously-curved anisotropic stripsApr 20 2011Dec 07 2011Multistable structures are objects with more than one stable conformation, exemplified by the simple switch. Continuum versions are often elastic composite plates or shells, such as the common measuring tape or the slap bracelet, both of which exhibit ... More
VZ Velorum: 116 years of a Mira starJun 01 2006Using the Harvard College Observatory Photographic Plate Collection and recent CCD observations by the ASAS project we have reconstructed the light variations of the southern pulsating red giant star VZ Velorum between 1890 and early 2006. Contrary to ... More
Results on D+-->lv and Ds+-->lv decays at Charm factoryMay 07 2013Jun 07 2013In this article, we reviewed the results on D+-->lv and Ds+-->lv decays at Charm factory.
Wireless Josephson Junction Arrays as Tunable Metamaterials: Inducing Discrete Frequency Steps with Microwave RadiationJan 23 2015We report low temperature, microwave transmission measurements on a new switchable and tunable class of nonlinear metamaterials. A wireless two dimensional array of Josephson junctions (JJ) is probed as a metamaterial where each plaquette in the array ... More
Anisotropy of the superconducting fluctuations in multiband superconductors: the case of LiFeAsJul 08 2014Nov 14 2014Between the different families of pnictide multiband superconductors, LiFeAs is probably one of the less understood. Indeed, despite the large amount of experiments performed in the last few years on this material, no consensus has been reached yet on ... More
Gedanken Experiments involving Black HolesAug 20 1993Analysis of several gedanken experiments indicates that black hole complementarity cannot be ruled out on the basis of known physical principles. Experiments designed by outside observers to disprove the existence of a quantum-mechanical stretched horizon ... More
On the measure of Lagrangian invariant tori in nearly--integrable mechanical systems (draft)Mar 27 2015Consider a real--analytic nearly--integrable mechanical system with potential $f$, namely, a Hamiltonian system, having a real-analytic Hamiltonian $$ H(y,x)=\frac12 | y |^2 +\e f(x)\ , $$ $y,x$ being $n$--dimensional standard action--angle variables ... More
On the Evaluation and Comparison of Taggers: The Effect of Noise in Testing CorporaSep 28 1998This paper addresses the issue of {\sc pos} tagger evaluation. Such evaluation is usually performed by comparing the tagger output with a reference test corpus, which is assumed to be error-free. Currently used corpora contain noise which causes the obtained ... More
Poisson-Lie T-plurality of three-dimensional conformally invariant sigma models II: Nondiagonal metrics and dilaton puzzleAug 17 2004Sep 29 2005We look for 3-dimensional Poisson-Lie dualizable sigma models that satisfy the vanishing beta-function equations with constant dilaton field. Using the Poisson-Lie T-plurality we then construct 3-dimensional sigma models that correspond to various decompositions ... More
Classification of 6-dimensional real Manin triplesFeb 21 2002Mar 27 2002We present a complete list of 6-dimensional Manin triples or, equivalently, of 3-dimensional Lie bialgebras. We start from the well known classification of 3-dimensional real Lie algebras and assume the canonical bilinear form on the 6-dimensional Drinfeld ... More
Renormalizability of semiquantized fieldsOct 03 1994Sep 21 1995A definition is given, in the framework of stochastic quantization, for the dynamics of a system composed of classical and quantum degrees of freedom mutually interacting. It is found that the theory breaks reflection positivity, and hence it is unphysical. ... More
Leading order one-loop CP and P violating effective action in the Standard ModelFeb 11 2011The fermions of the Standard Model are integrated out to obtain the effective Lagrangian in the sector violating P and CP at zero temperature. We confirm that no contributions arise for operators of dimension six or less and show that the leading operators ... More
On a multidimentional Brownian motion with partly reflecting membrane on a hyperplaneOct 30 2012A multidimensional Brownian motion with partial reflection on a hyperplane $S$ in the direction $qN+\alpha $, where $N$ is the conormal vector to the hyperplane and $q\in [-1,1], \alpha \in S$ are given parametres, is constructed and this construction ... More
Supersymmetric domain wall x G/H solutions of IIB supergravityApr 23 20011-brane nonmaximally supersymmetric solutions of D=10 chiral supergravity are discussed. In the dual frame, their near brane geometry is the product of a 3-dimensional domain wall spacetime and a 7-dimensional homogeneous Einstein space G/H.
Hawking Radiation and Back-ReactionMar 20 1992The puzzles of black hole evaporation can be studied in the simplified context of 1+1 dimensional gravity. The semi-classical equations of Callan, Giddings, Harvey and Strominger provide a consistent description of the evaporation process which we describe ... More
Minimal surfaces bounded by elastic linesAug 02 2011May 30 2012In mathematics, the classical Plateau problem consists of finding the surface of least area that spans a given rigid boundary curve. A physical realization of the problem is obtained by dipping a stiff wire frame of some given shape in soapy water and ... More
Solution of a Yang-Baxter systemNov 04 1998Nov 05 1998Yang-Baxter system related to quantum doubles is introduced and large class of both continuous and discrete symmetries of the solution manifold are determined. Strategy for solution of the system based on the symmetries is suggested and accomplished in ... More
Does the complex Langevin method give unbiased results?Nov 19 2016We investigate whether the stationary solution of the Fokker-Planck equation of the complex Langevin algorithm reproduces the correct expectation values. When the complex Langevin algorithm for an action $S(x)$ is convergent, it produces an equivalent ... More
Comment on "Quantum back-reaction through the Bohmian particle"Feb 17 2003In this Comment I point out some limitations of the proposal of Prezhdo and Brooksby for coupling quantum and classical degrees of freedom (Phys.Rev.Lett.86(2001)3215) if it is pushed too far.
Generalized heat kernel coefficientsJul 16 2001Sep 26 2001Following Osipov and Hiller, a generalized heat kernel expansion is considered for the effective action of bosonic operators. In this generalization, the standard heat kernel expansion, which counts inverse powers of a c-number mass parameter, is extended ... More
Comment on ``A quantum-classical bracket that satisfies the Jacobi identity'' [J. Chem. Phys. 124, 201104 (2006)]Jan 10 2007It shown that the quantum-classical dynamical bracket recently proposed in J. Chem. Phys. 124, 201104 (2006) fails to satisfy the Jacobi identity.
Minimum uncertainty for antisymmetric wave functionsJun 05 1997We study how the entropic uncertainty relation for position and momentum conjugate variables is minimized in the subspace of one-dimensional antisymmetric wave functions. Based partially on numerical evidence and partially on analytical results, a conjecture ... More
Chiral asymmetry of the spin-wave spectra in ultrathin magnetic filmsJan 19 2009We raise the possibility that the chiral degeneracy of the magnons in ultrathin films can be lifted due to the presence of Dzyaloshinskii-Moriya interactions. By using simple symmetry arguments, we discuss under which conditions such a chiral asymmetry ... More
Optical Doppler shift measurement using a rotating mirrorJul 24 2006Sep 22 2006Optical Doppler shift demonstration experiments are not a simple task since the light source cannot usually be moved in a sufficiently smooth and uniform manner to keep the level of noise well below of that of the signal. For that reason most demonstration ... More
Positive representations of complex distributions on groupsMay 04 2018Oct 29 2018A normalizable complex distribution $P(x)$ on a manifold $\mathcal{M}$ can be regarded as a complex weight, thereby allowing to define expectation values of observables $A(x)$ defined on $\mathcal{M}$. Straightforward importance sampling, $x\sim P$, is ... More
Stability of a Time-varying Fishing Model with DelayJan 19 2006We introduce a delay nonlinear differential equation model which describes how fish are harvested. In our previous studies we investigated the persistence of that equation and existence of a periodic solution for this equation. Here we study the stability ... More
Constraints on star formation theories from the Serpens molecular cloud and protoclusterJul 10 2002We have mapped the large-scale structure of the Serpens cloud core using moderately optically thick (13CO(1--0) and CS(2--1)) and optically thin tracers (C18O(1--0), C34S(2--1), and N2H+(1--0)), using the 16-element focal plane array operating at a wavelength ... More
Classification of Poisson-Lie T-dual models with two-dimensional targetsOct 16 2001Dec 20 2001Four-dimensional Manin triples and Drinfeld doubles are classified and corresponding two-dimensional Poisson-Lie T-dual sigma models on them are constructed. The simplest example of a Drinfeld double allowing decomposition into two nontrivially different ... More
Statistical Mechanics of Developable RibbonsFeb 24 2010Jun 11 2010We investigate the statistical mechanics of long developable ribbons of finite width and very small thickness. The constraint of isometric deformations in these ribbon-like structures that follows from the geometric separation of scales introduces a coupling ... More