UScholar Works
 
Filters: Format: "application/pdf" Journal Title: "Physical Review A" Collection: "ir_uspace"
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CreatorTitleDescriptionSubjectDate
1 Wu, Yong-ShiAlgebraic solution for a two-level atom in radiation fields and the Freeman resonancesUsing techniques of complex analysis in an algebraic approach, we solve the wave equation for a two-level atom interacting with a monochromatic light field exactly. A closed-form expression for the quasienergies is obtained, which shows that the Bloch-Siegert shift is always finite, regardless of ...Bloch-Siegert shift; Freeman resonances; Quasienergies2006-02
2 Mattis, Daniel C.; Sutherland, BillAmbiguities with the relativistic δ-function potentialIn many cases of physical interest, the 6-function potential is a very convenient approximation to more structured, and more difficult, short-ranged potentials. In relativistic theories, its use is often mandated because only a mathematical point has a relativistically invariant shape. Neverthele...Delta function; Energy states1981-09
3 Mattis, Daniel C.Critical curves and thermodynamic phases of lattice fluids and antiferromagnets with structured interactionsWe study the classical lattice gas with hard cores, nearest-neighbor repulsive forces, and next-nearest-neighbor attractive forces. We find several thermodynamic phases (vapor, liquid, and solid) and unusually shaped critical curves, yet no critical point or triple point. We find and discuss discont...Ising antiferromagnet; Molecular field theory1971-06
4 Gerton, JordanDipolar relaxation collisions in magnetically trapped 7LiWe report the measurement of the rate constant for dipolar relaxation from the (F=2, mF=2) hyperfine state of 7Li. The atoms are confined in a permanent magnet trap at a field of 10^3 G. The measured value of (1.05±0.10)X10^-14 cm3/s agrees well with theory. Additionally, we determine an upper bo...1999-02
5 Vardeny, Zeev Valentine; Raikh, Mikhail E.Excitations in photonic crystals infiltrated with polarizable mediaLight propagation in a photonic crystal with incomplete band gap, infiltrated with polarizable molecules is considered. We demonstrate that the interplay between the spatial dispersion caused by Bragg diffraction and polaritonic frequency dispersion gives rise to alternative propagating excitation...Polarizable media; Light propagation; Bragg diffraction; Excitations2001-06
6 Mishchenko, EugeneFluctuations of radiation from a chaotic laser below thresholdRadiation from a chaotic cavity filled with gain medium is considered. A set of coupled equations describing the photon density and the population of gain medium is proposed and solved. The spectral distribution and fluctuations of the radiation are found. The full noise is a result of a competitio...Chaotic laser2004-03
7 Saam, Brian; Pugmire, Ronald J.Gas-phase spin relaxation of 129XeWe have completed an extensive study of 129Xe longitudinal spin relaxation in the gas phase, involving both intrinsic and extrinsic mechanisms. The dominant intrinsic relaxation is mediated by the formation of persistent Xe2 van der Waals dimers. The dependence of this relaxation on applied magnetic...129Xe; Gas-phase spin relaxation2008-10
8 Wu, Yong-ShiHigh-precision quasienergies for a driven two-level atom at the two-photon preresonanceA computation with unprecedented precision is presented for quasienergies of a two-level atom in a monochromatic radiation on the basis of a recently obtained exact expression [D.-S. Guo et al., Phys. Rev. A 73,023419 (2006)]. We start with the proof of an expression theorem. With this theorem the ...Quasienergies; Preresonance; Floquet periodicity2008-02
9 Gerton, JordanLaser-free slow atom sourceA slow atom source, which does not rely on lasers, has been developed and characterized. The device, acting as an atomic low-pass velocity filter, utilizes permanent magnets to passively select the slow atoms present in a thermal atomic beam. Slow atoms are guided along a curved, conduction-limite...1999-11
10 Saam, BrianLow-field orientation dependence of 3He relaxation in spin-exchange cellsWe have observed a significant dependence of 3He longitudinal relaxation times in glass spin-exchange optical pumping (SEOP) cells due only to the physical orientation of the cell in a 3 mT (30 G) applied magnetic field. The cells had no previous exposure to higher fields or were thoroughly degau...Spin-exchange optical pumping; SEOP; 3He; Hyperpolarized noble gases; Longitudinal spin-relaxation; MEOP; Low-field orientation2004-02
11 Saam, Brian; Laicher, GernotNuclear spin relaxation of 129Xe due to persistent xenon dimersWe have measured longitudinal nuclear relaxation rates of 129Xe in Xe-N2 mixtures at densities below 0.5 amagats in a magnetic field of 8.0 T. We find that intrinsic spin relaxation in this regime is principally due to fluctuations in the intramolecular spin-rotation (SR) and chemical-shift-anisot...Nuclear spin relaxation; Xe129; Xenon dimmers2006-12
12 Wu, Yong-ShiPerturbative formulation and nonadiabatic corrections in adiabatic quantum-computing schemesAdiabatic limit is the presumption of the adiabatic geometric quantum computation and of the adiabatic quantum algorithm. But in reality, the variation speed of the Hamiltonian is finite. Here we develop a general formulation of adiabatic quantum computing, which accurately describes the evolution...Perturbative formulation; Nonadiabatic corrections; Adiabatic2004-02
13 Gerton, JordanPhotoassociative frequency shift in a quantum degenerate gasA light-induced frequency shift is observed in single-photon photoassociative spectra of magnetically trapped, quantum degenerate 7Li. The shift is a manifestation of the coupling between the threshold continuum scattering states and discrete bound levels in the excited-state molecular potential in...2001-10
14 Wu, Yong-ShiQuantum phase transition in a multicomponent Bose-Einstein condensate in optical latticesWe present a general lattice model for a multicomponent atomic Bose-Einstein system in an optical lattice. Using the model, we analytically study the quantum phase transition between the Mott insulator and a superfluid. A mean-field theory is developed from the Mott-insulator ground state. When the...Quantum phase transitions; Optical lattices; Bose-Einstein condensation; Boson-Hubbard model; Superfluids2003-01
15 Wu, Yong-ShiResonant above-threshold ionization at quantized laser intensitiesWe argue that quantum electrodynamics dictates resonance phenomena in multiphoton processes as the laser intensity varies. A perturbation theory is developed in which the coupling between an electron and the second quantized laser mode is treated nonperturbatively. As an example, we predict that th...Laser field; Volkov states2000-03
16 Wu, Yong-ShiSchrödinger-like equation for a nonrelativistic electron in a photon field of arbitrary intensityThe Schrödinger equation with minimal coupling for a nonrelativistic electron interacting with a single-mode photon field is not satisfied by the nonrelativistic limit of the exact solutions to the corresponding Dirac equation. A Schrödinger-like equation valid for arbitrary photon intensity is d...Photon field; Nonrelativistic electron1998-07
17 Gerton, JordanSinglet s-wave scattering lengths of 6Li and 7LiPhotoassociation of ultracold lithium atoms into bound vibrational levels of the A 1Σu+ excited state is used to probe the X1Σg+ ground-state interaction potential of 6Li2 and 7Li2 . It had been predicted that the s-wave photoassociation signal strength would pass through a minimum as a function...1996-06
18 Gerton, JordanTriplet s-wave resonance in 6Li collisions and scattering lengths of 6Li and 7LiThe triplet s-wave scattering length of 6Li is determined using two-photon photoassociative spectroscopy of the diatomic α 3Σu+ state of 6Li2. The measured binding energy of the highest-lying bound state, combined with knowledge of the potential, determines the s-wave scattering length to be -21...1997-05
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