11,640 research outputs found
Basic Representations of A_{2l}^(2) and D_{l+1}^(2) and the Polynomial Solutions to the Reduced BKP Hierarchies
Basic representations of A_{2l}^(2) and D_{l+1}^(2) are studied. The weight
vectors are represented in terms of Schur's -functions. The method to get
the polynomial solutions to the reduced BKP hierarchies is shown to be
equivalent to a certain rule in Maya game.Comment: January 1994, 11 page
Ground state properties of one-dimensional Bose-Fermi mixtures
Bose-Fermi mixtures in one dimension are studied in detail on the basis of an
exact solution. Corresponding to three possible choices of the referecce state
in the quantum inverse scattering method, three sets of Bethe-ansatz equations
are derived explicitly. The features of the ground state and low-lying
excitations are investigated. The ground state phase diagram caused by the
external field and chemical potential is obtained
Controllable manipulation and entanglement of macroscopic quantum states in coupled charge qubits
We present an experimentally implementable method to couple Josephson charge
qubits and to generate and detect macroscopic entangled states. A
large-junction superconducting quantum interference device is used in the qubit
circuit for both coupling qubits and implementing the readout. Also, we
explicitly show how to achieve a microwave-assisted macroscopic entanglement in
the coupled-qubit system.Comment: 8 pages, 4 figure
Transforming U.S. Particle Physics Education: A Snowmass 2021 Study
The pursuit of knowledge in particle physics requires constant learning. As
new tools become available, new theories are developed, and physicists search
for new answers with ever-evolving methods. However, it is the case that formal
educational systems serve as the primary training grounds for particle
physicists. Graduate school (and undergraduate school to a lesser extent) is
where researchers learn most of the technical skills required for research,
develop scientific problem-solving abilities, learn how to establish themselves
in their field, and begin developing their career. It is unfortunate, then,
that the skills gained by physicists during their formal education are often
mismatched with the skills actually required for a successful career in
physics. We performed a survey of the U.S. particle physics community to
determine the missing elements of graduate and undergraduate education and to
gauge how to bridge these gaps. In this contributed paper, part of the 2021-22
Snowmass Community Planning Exercise, we report the results of this survey. We
also recommend several specific community actions to improve the quality of
particle physics education; the "community" here refers to physics departments,
national labs, professional societies, funding agencies, and individual
physicists.Comment: contribution to Snowmass 202
Quantum information processing with superconducting qubits in a microwave field
We investigate the quantum dynamics of a Cooper-pair box with a
superconducting loop in the presence of a nonclassical microwave field. We
demonstrate the existence of Rabi oscillations for both single- and
multi-photon processes and, moreover, we propose a new quantum computing scheme
(including one-bit and conditional two-bit gates) based on Josephson qubits
coupled through microwaves.Comment: 7 pages, 1 figur
Magnetic properties of an SU(4) spin-orbital chain
In this paper, we study the magnetic properties of the one-dimensional SU(4)
spin-orbital model by solving its Bethe ansatz solution numerically. It is
found that the magnetic properties of the system for the case of
differs from that for the case of . The magnetization curve and
susceptibility are obtained for a system of 200 sites. For , the
phase diagram depending on the magnetic field and the ratio of Land\'e factors,
, is obtained. Four phases with distinct magnetic properties are
found.Comment: 4 pages, 2 figure
Phase diagram and symmetry breaking of SU(4) spin-orbital chain in a generalized external field
The ground state phases of a one-dimensional SU(4) spin-orbital Hamiltonian
in a generalized external field are studied on the basis of Bethe-ansatz
solution. Introducing three Land\'e factors for spin, orbital and their
products in the SU(4) Zeeman term, we discuss systematically the various
symmetry breaking. The magnetization versus external field are obtained by
solving Bethe-ansatz equations numerically. The phase diagrams corresponding to
distinct residual symmetries are given by means of both numerical and
analytical methods.Comment: Revtex4, 16 pages, 7 figure
Observation of momentum-confined in-gap impurity state in BaKFeAs: evidence for anti-phase pairing
We report the observation by angle-resolved photoemission spectroscopy of an
impurity state located inside the superconducting gap of
BaKFeAs and vanishing above the superconducting
critical temperature, for which the spectral weight is confined in momentum
space near the Fermi wave vector positions. We demonstrate, supported by
theoretical simulations, that this in-gap state originates from weak
non-magnetic scattering between bands with opposite sign of the superconducting
gap phase. This weak scattering, likely due to off-plane Ba/K disorders, occurs
mostly among neighboring Fermi surfaces, suggesting that the superconducting
gap phase changes sign within holelike (and electronlike) bands. Our results
impose severe restrictions on the models promoted to explain high-temperature
superconductivity in these materials.Comment: 8 pages, 5 figures. Accepted for publication in Physical Review
Diffusive transport of light in two-dimensional granular materials
We study photon diffusion in a two-dimensional random packing of monodisperse
disks as a simple model of granular material. We apply ray optics approximation
to set up a persistent random walk for the photons. We employ Fresnel's
intensity reflectance with its rich dependence on the incidence angle and
polarization state of the light. We present an analytic expression for the
transport-mean-free path in terms of the refractive indices of grains and host
medium, grain radius, and packing fraction. We perform numerical simulations to
examine our analytical result.Comment: 9 pages, 3 figure
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