A5002867751- Quantum Information and Cryptography
- Particle Accelerators and Free-Electron Lasers
- Quantum Computing Algorithms and Architecture
- Quantum Mechanics and Applications
- Quantum optics and atomic interactions
- Advanced X-ray Imaging Techniques
- Quantum and electron transport phenomena
- Atomic and Subatomic Physics Research
- Cold Atom Physics and Bose-Einstein Condensates
- Mechanical and Optical Resonators
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- Crystallography and Radiation Phenomena
- Laser-Matter Interactions and Applications
- Electron and X-Ray Spectroscopy Techniques
- Spectroscopy and Quantum Chemical Studies
- Photonic and Optical Devices
- Electromagnetic Simulation and Numerical Methods
- Neural Networks and Reservoir Computing
- Blind Source Separation Techniques
- Optical Network Technologies
- Adrenal and Paraganglionic Tumors
- Advanced NMR Techniques and Applications
- Advanced Electron Microscopy Techniques and Applications
- Orbital Angular Momentum in Optics
Los Alamos National Laboratory
2015-2024
Louisiana State University
2009-2014
Texas A&M University
2004-2011
Institute of Applied Physics
2003
We study the sensitivity and resolution of phase measurement in a Mach-Zehnder interferometer with two-mode squeezed vacuum (<n> photons on average). show that super-resolution sub-Heisenberg is obtained parity detection. In particular, our setup, dependence signal evolves <n> times faster than traditional schemes, uncertainty estimation better 1/<n>.
Autler-Townes splitting (ATS) and electromagnetically induced transparency (EIT) both yield in an absorption profile, but only EIT yields strong for a weak pump field due to Fano interference. Empirically discriminating from ATS is important so far has been subjective. We introduce objective method, based on Akaike's information criterion, test vs experimental data three-level atomic systems determine which pertains. apply our method recently reported induced-transparency experiment...
As quantum computers become available to the general public, need has arisen train a cohort of programmers, many whom have been developing classical computer programs for most their careers. While currently less than 100 qubits, computing hardware is widely expected grow in terms qubit count, quality, and connectivity. This review aims explain principles programming, which are quite different from with straightforward algebra that makes understanding underlying fascinating mechanical...
The variational quantum eigensolver (VQE) is one of the most promising algorithms to find eigenvalues and eigenvectors a given Hamiltonian on noisy intermediate-scale (NISQ) devices. A particular application obtain ground or excited states molecules. practical realization currently limited by complexity circuits. Here we present novel approach reduce circuit in VQE for electronic structure calculations. Our algorithm, called ClusterVQE, splits initial qubit space into subspaces (qubit...
The interference between coherent and squeezed vacuum light can produce path entangled states with very high fidelities. We show that the phase sensitivity of above interferometric scheme parity detection saturates quantum Cramer-Rao bound, which reaches Heisenberg-limit when are mixed in roughly equal proportions. For same scheme, we draw a detailed comparison symmetric-logarithmic-derivative-based suggested by Ono Hofmann.
In the field of beam physics, two frontier topics have taken center stage due to their potential enable new approaches discovery in a wide swath science. These areas are: advanced, high gradient acceleration techniques, and x-ray free electron lasers (XFELs). Further, there is intense interest marriage these fields, with goal producing very compact XFEL. this context, recent advances radio-frequency cryogenic copper structure research opened door use surface electric fields between 250 500...
There has been much recent interest in quantum optical interferometry for applications to metrology, subwavelength imaging, and remote sensing such as laser radar (LADAR). For LADAR, atmospheric absorption rapidly degrades any state of light, so that high-photon loss the optimal strategy is transmit coherent states which suffer no worse than Beer law classical attenuation, provides sensitivity at shot-noise limit. We show light coupled with photon-number-resolving detectors can provide a...
We introduce decaying-dressed states for a three-level Λ system driven at one atomic transition and probed the adjacent one. These allow simple interpretation classification of various coherent effects in such system.
Design methodologies for high-performance photocathodes become increasingly important, driven by the needs of advanced x-ray light sources and ultrafast electron diffraction microscopy. Cathode design has been hampered interdependent performance metrics, where improving one compromises another. Rapid developments in modeling nanomaterial fabrication allow tailoring electronic structure ways that influence fundamental mechanisms photoemission: absorption, transport, emission. This survey...
A proposed phase-estimation protocol based on measuring the parity of a two-mode squeezed-vacuum state at output Mach-Zehnder interferometer shows that Cram\'er-Rao sensitivity is sub-Heisenberg [P. M. Anisimov et al., Phys. Rev. Lett. 104, 103602 (2010)]. However, these measurements are problematic, making it unclear if this can be obtained with finite number measurements. This only for phase near zero, and in region there problem ambiguity because cannot distinguish sign phase. Here, we...
We present a method of directly obtaining the parity Gaussian state light without recourse to photon-number counting.The scheme uses only simple balanced homodyne technique, and intensity correlation.Thus interferometric schemes utilizing coherent or squeezed light, detection may be practically implemented for an arbitrary photon flux.Specifically we investigate two-mode, squeezed-light, Mach-Zehnder interferometer show how output obtained.We also that described independent operator, this...
We present an experimental and theoretical study of the carrier-envelope phase effects on population transfer between two bound atomic states interacting with intense ultrashort pulses. Radio frequency pulses are used to among ground state hyperfine levels in rubidium atoms. These only a few cycles duration have Rabi frequencies order carrier frequency. The difference envelope has significant effect excitation coherence transfer. provide description this phenomenon using density matrix...
Abstract The possibility of using quantum computers for electronic structure calculations has opened up a promising avenue computational chemistry. Towards this direction, numerous algorithmic advances have been made in the last five years. potential annealers, which are prototypes adiabatic computers, is yet to be fully explored. In work, we demonstrate use D-Wave annealer calculation excited states molecular systems. These simulations play an important role number areas, such as...
Defining a computational basis of pseudo-number states, we interpret coherent state large amplitude, |α|⪢d/2π, as qudit — d-level quantum system that is an even (meaning same size amplitudes) superposition d states. A pair such coherent-state qudits can be maximally entangled by generalized Controlled-Z operation based on cross-Kerr nonlinearity, which weak for d. Hence, optical cluster prepared repetitive application the to set We thus propose teleportation simple demonstration computation.
Enhancement and control of the index refraction in a mixture two three-level atomic species that form pair far-detuned $\ensuremath{\Lambda}$ schemes under two-photon resonance has been studied. We employ density-matrix approach to properly take population relaxation into account describe interaction each system with electromagnetic fields. Both systems are driven by corresponding coherent field at one transition probed same weak field. In dressed-state basis, it represents superposition...
Quantum chemistry is interested in calculating ground and excited states of molecular systems by solving the electronic Schrödinger equation. The exact numerical solution this equation, frequently represented as an eigenvalue problem, remains unfeasible for most molecules requires approximate methods. In paper we introduce use Community Detection performed using D-Wave quantum annealer to reduce Hamiltonian matrix Slater determinant basis without chemical knowledge. Given a molecule...
The radial Schrodinger equation for a spherically symmetric potential can be regarded as one-dimensional classical harmonic oscillator with time-dependent spring constant. For solving dynamics problems, symplectic integrators are well known their excellent conservation properties. class of gradient algorithms is particularly suited harmonic-oscillator dynamics. By use Suzuki's rule [Proc. Jpn. Acad., Ser. B: Phys. Biol. Sci. 69, 161 (1993)] decomposing time-ordered operators, these easily...
We show a simulation of quantum random walks (QRWs) with multiple photons using staggered array 50/50 beam splitters bank detectors at any desired level. discuss the multiphoton interference effects that are inherent to this setup, and introduce one, two, threefold coincidence detection schemes. Feynman diagrams used intuitively explain unique these QRWs.
One of the major challenges in quantum computation has been to preserve coherence a system against dephasing effects environment. The information stored photon polarization, for example, is quickly lost due such dephasing, and it crucial input states when one tries transmit encoded photons through communication channel. We propose dynamical decoupling sequence protect photonic qubits from by integrating wave plates into optical fiber at prescribed locations. simulate random birefringent...
We present a numerical study of the properties optical forces on moving atoms derived from purely stimulated processes produced by multiple adiabatic rapid-passage sequences. The Bloch equations are solved for carefully timed sequence frequency-swept pulses that can produce force much larger than ordinary radiative force. describe effects sweep range, peak intensity, direction, number pulses, atomic velocity, and spontaneous emission. Since momentum thermal is transferred single...
A fully quantized analysis is presented of induced magneto-electric rectification in individual diatomic molecules the steady-state regime. Good agreement obtained between this quantum theory and a classical model that includes same key kinematic elements but predicts temporal dynamics as well. At molecular level, an enhanced optical interaction driven by dual fields E H* shown to give rise static electric dipole (ED) moment oriented along propagation direction linearly-polarized light...
A future capability in dynamic mesoscale materials science is needed to study the limitations of under irreversible and extreme conditions, where these are caused by nonuniformities defects mesoscale. This gap could potentially be closed with an X-ray free-electron laser (XFEL), producing 5 × 1010 photons energy 42 keV, known as Matter–Radiation Interactions Extremes (MaRIE) XFEL. Over last few years, researchers at Los Alamos National Laboratory have developed a preconceptual design for...
Recently, considerable work has been directed at development of a ultra-compact X-ray free-electron laser based on emerging techniques in high field cryogenic acceleration, with attendant dramatic improvements electron beam brightness, and state-of-the-art concepts dynamics, magnetic undulators, optics. A full conceptual design 1 nm XFEL length cost over an order magnitude below current XFELs resulted from this effort. This instrument developed emphasis permitting exploratory scientific...