828 research outputs found
Quantum Numbers of Textured Hall Effect Quasiparticles
We propose a class of variational wave functions with slow variation in spin
and charge density and simple vortex structure at infinity, which properly
generalize both the Laughlin quasiparticles and baby Skyrmions. We argue that
the spin of the corresponding quasiparticle has a fractional part related in a
universal fashion to the properties of the bulk state, and propose a direct
experimental test of this claim. We show that certain spin-singlet quantum Hall
states can be understood as arising from primary polarized states by Skyrmion
condensation.Comment: 13 pages, no figures, Phyzz
Optical injection and terahertz detection of the macroscopic Berry curvature
We propose an experimental scheme to probe the Berry curvature of solids. Our
method is sensitive to arbitrary regions of the Brillouin zone, and employs
only basic optical and terahertz techniques to yield a background free signal.
Using semiconductor quantum wells as a prototypical system, we discuss how to
inject Berry curvature macroscopically, and probe it in a way that provides
information about the underlying microscopic Berry curvature.Comment: 4 pages, accepted in Physical Review Letter
Mesons and Nucleons in Soft-Wall AdS/QCD with Constrained Infrared Background
The purpose of this paper is to further study the soft-wall AdS/QCD model
with constrained IR background. By including a quartic bulk scalar potential we
study various meson and nucleon spectra. This model naturally realizes the
asymptotical linearity of these mass spectra simultaneously, together with
correctly pattern of explicit and dynamical chiral symmetry breaking. The
agreement between the theoretical calculations and the experimental data is
good.Comment: 17 pages,5 table
Origins of Mass
Newtonian mechanics posited mass as a primary quality of matter, incapable of
further elucidation. We now see Newtonian mass as an emergent property. Most of
the mass of standard matter, by far, arises dynamically, from back-reaction of
the color gluon fields of quantum chromodynamics (QCD). The equations for
massless particles support extra symmetries - specifically scale, chiral, and
gauge symmetries. The consistency of the standard model relies on a high degree
of underlying gauge and chiral symmetry, so the observed non-zero masses of
many elementary particles ( and bosons, quarks, and leptons) requires
spontaneous symmetry breaking. Superconductivity is a prototype for spontaneous
symmetry breaking and for mass-generation, since photons acquire mass inside
superconductors. A conceptually similar but more intricate form of
all-pervasive (i.e. cosmic) superconductivity, in the context of the
electroweak standard model, gives us a successful, economical account of
and boson masses. It also allows a phenomenologically successful, though
profligate, accommodation of quark and lepton masses. The new cosmic
superconductivity, when implemented in a straightforward, minimal way, suggests
the existence of a remarkable new particle, the so-called Higgs particle. The
mass of the Higgs particle itself is not explained in the theory, but appears
as a free parameter. Earlier results suggested, and recent observations at the
Large Hadron Collider (LHC) may indicate, the actual existence of the Higgs
particle, with mass GeV. In addition to consolidating our
understanding of the origin of mass, a Higgs particle with
GeV could provide an important clue to the future, as it is consistent with
expectations from supersymmetry.Comment: Invited review for the Central European Journal of Physics. This is
the supplement to my 2011 Solvay Conference talk promised there. It is
adapted from an invited talk given at the Atlanta APS meeting, April 2012. 33
pages, 6 figures. v2: Added update section bringing in the CERN discovery
announcemen
Fractional Statistics in Three Dimensions: Compact Maxwell-Higgs System
We show that a (3+1)-dimensional system composed of an open magnetic vortex
and an electrical point charge exhibits the phenomenon of Fermi-Bose
transmutation. In order to provide the physical realization of this system we
focus on the lattice compact scalar electrodynamics whose topological
excitations are open Nielsen-Olesen strings with magnetic monopoles attached at
their ends.Comment: 8 page
Bosonization and phase Diagram of the one-dimensional t-J model
We present an analytic study of the phase diagram of the one-dimensional t-J
model and a couple of its cousins. To deal with the interactions induced by the
no double occupancy constraints, we introduce a deformation of the Hubbard
operators. When the deformation parameter is small, the induced
interactions are softened, accessible by perturbation theory. We combine
bososnization with renormalization group techniques to map out the phase
diagram of the system. We argue that when , there is no essential
change in the phase diagram. Comparison with the existing results in the
literature obtained by other methods justifies our deformation approach.Comment: 24 pages, 1 Figur
Extended axion electrodynamics: Optical activity induced by nonstationary dark matter
We establish a new self-consistent Einstein-Maxwell-axion model based on the
Lagrangian, which is linear in the pseudoscalar (axion) field and its
four-gradient and includes the four-vector of macroscopic velocity of the axion
system as a whole. We consider extended equations of the axion electrodynamics,
modified gravity field equations, and discuss nonstationary effects in the
phenomenon of optical activity induced by axions.Comment: 6 pages, 0 figures, accepted for publication in the Journal
Gravitation and Cosmology, reported at the 14th Russian Gravitational
Conference (Ulyanovsk, 2011
Exact Wavefunctions for non-Abelian Chern-Simons Particles
Exact wavefunctions for N non-Abelian Chern-Simons (NACS) particles are
obtained by the ladder operator approach. The same method has previously been
applied to construct exact wavefunctions for multi-anyon systems. The two
distinct base states of the NACS particles that we use are multi-valued and are
defined in terms of path ordered line integrals. Only strings of operators that
preserve the monodromy properties of these base states are allowed to act on
them to generate new states.Comment: 19 pages, CALT-68-187
A doubled discretisation of abelian Chern-Simons theory
A new discretisation of a doubled, i.e. BF, version of the pure abelian
Chern-Simons theory is presented. It reproduces the continuum expressions for
the topological quantities of interest in the theory, namely the partition
function and correlation function of Wilson loops. Similarities with free
spinor field theory are discussed which are of interest in connection with
lattice fermion doubling.Comment: 5 pages, revtex, 2 ps figures (epsf required). To appear in
Phys.Rev.Let
Detailed Balance and Intermediate Statistics
We present a theory of particles, obeying intermediate statistics ("anyons"),
interpolating between Bosons and Fermions, based on the principle of Detailed
Balance. It is demonstrated that the scattering probabilities of identical
particles can be expressed in terms of the basic numbers, which arise naturally
and logically in this theory. A transcendental equation determining the
distribution function of anyons is obtained in terms of the statistics
parameter, whose limiting values 0 and 1 correspond to Bosons and Fermions
respectively. The distribution function is determined as a power series
involving the Boltzmann factor and the statistics parameter and we also express
the distribution function as an infinite continued fraction. The last form
enables one to develop approximate forms for the distribution function, with
the first approximant agreeing with our earlier investigation.Comment: 13 pages, RevTex, submitted for publication; added references; added
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