1,907 research outputs found
Fundamental Cycle of a Periodic Box-Ball System
We investigate a soliton cellular automaton (Box-Ball system) with periodic
boundary conditions. Since the cellular automaton is a deterministic dynamical
system that takes only a finite number of states, it will exhibit periodic
motion. We determine its fundamental cycle for a given initial state.Comment: 28 pages, 6 figure
Direct observation of the multiple spin gap excitations in two-dimensional dimer system SrCu2(BO3)2
Various spin gap excitations have been observed in the two-dimensional dimer
system SrCu_2(BO_3)_2 by means of submillimeter wave ESR. The zero-field energy
gap of the lowest spin gap excitation shows a splitting into two triplet modes
and the energy splitting clearly depends on the magnetic field orientation when
a field is rotated in the {\mib {ac}}-plane. A zero-field splitting is also
found between the S(_z)=+1 and S(_z)=-1 branches of each triplet. These
behaviors are qualitatively explained by considering the anisotropic exchange
coupling of inter-dimer and intra-dimer, respectively. The averaged value of
the lowest spin gap energy is determined to be 722 \pm 2 GHz(34.7 K). We have
also found the second spin gap excitation at 1140 GHz(54.7 K), which indicates
that the inter-dimer coupling is significantly strong. Besides these modes, a
number of gapped ESR absorption are found and we propose that these multiple
magnetic excitations are caused by the localized nature of the excited state in
the present system.Comment: 4pages 4figure
The Q-operator and Functional Relations of the Eight-vertex Model at Root-of-unity for odd N
Following Baxter's method of producing Q_{72}-operator, we construct the
Q-operator of the root-of-unity eight-vertex model for the crossing parameter
with odd where Q_{72} does not exist. We use this
new Q-operator to study the functional relations in the Fabricius-McCoy
comparison between the root-of-unity eight-vertex model and the superintegrable
N-state chiral Potts model. By the compatibility of the constructed Q-operator
with the structure of Baxter's eight-vertex (solid-on-solid) SOS model, we
verify the set of functional relations of the root-of-unity eight-vertex model
using the explicit form of the Q-operator and fusion weights of SOS model.Comment: Latex 28 page; Typos corrected, minor changes in presentation,
References added and updated-Journal versio
Magnetism and superconductivity in TaSC (M = Fe, Co, Ni, and Cu)
Magnetic properties of TaSC ( = Fe, Co, Ni, Cu) have
been studied using SQUID DC and AC magnetic susceptibility. In these systems
magnetic ions are intercalated into van der Waals gaps between
adjacent S layers of host superconductor TaSC.
FeTaSC is a quasi 2D -like antiferromagnet on the
triangular lattice. It undergoes an antiferromagnetic phase transition at
(= 117 K). The irreversible effect of magnetization occurs below
, reflecting the frustrated nature of the system. The AF phase coexists
with two superconducting phases with the transition temperatures
K and K. CoTaSC is a quasi 2D Ising-like
antiferromagnet on the triangular lattice. The antiferromagnetic phase below
K coexists with a superconducting phase below K.
Both NiTaSC and CuTaSC are
superconductors with ( K for Ni and 6.4 K for Cu) and
(= 4.6 K common to TaSC). Very small effective magnetic
moments suggest that Ni and Cu spins are partially delocalized.Comment: 15 pages, 17 figures, and 3 table
Novel classical ground state of a many body system in arbitrary dimensions
The classical ground state of a D- dimensional many body system with two and
three body interactions is studied as a function of the strength of the three
body interaction. We prove exactly that beyond a critical strength of the three
body interaction, the classical ground state of the system is one in which all
the particles are on a line. The positions of the particles in this string
configuration are uniquely determined by the zeros of the Hermite polynomials.Comment: 4 pages, RevTeX, no figure; version to appear in Physical Review
Letter
Chemical passivation of unstable FeO - a Mossbauer study
Highly unstable FeO is chemically passivated by incorporating Cr3+ ions by solid solution technique and forming FexO:Cr3+ single phase material. XRD, chemical analysis and Mossbauer spectroscopy are used for the characterization of the freshly prepared as well as samples aged in the desiccator for nearly three months. Optimum concentration range - 0.25 to 0.75 mole% - of Cr2O3 has been found to be necessary for stabilizing FexO:Cr3+. x is determined by chemical analysis. Mossbauer and XRD studies have confirmed the chemical passivation of unstable FeO
Dual Resonance Model Solves the Yang-Baxter Equation
The duality of dual resonance models is shown to imply that the four point
string correlation function solves the Yang-Baxter equation. A reduction of
transfer matrices to symmetry is described by a restriction of the KP
function to Toda molecules.Comment: 10 pages, LaTe
Stabilization of high Tc phase in bismuth cuprate superconductor by lead doping
It has been widely ascertained that doping of lead in Bi-Sr-Ca-Cu-O systems promotes the growth of high T sub c (110 K) phase, improves critical current density, and lowers processing temperature. A systematic study was undertaken to determine optimum lead content and processing conditions to achieve these properties. A large number of samples with cationic compositions of Bi(2-x)Pb(x)Sr2Ca2Cu3 (x = 0.2 to 2.0) were prepared by conventional solid state reaction technique. Samples of all compositions were annealed together at a temperature and characterized through resistance temperature (R-T) measurements and x ray diffraction to determine the zero resistance temperature, T sub c(0) and to identify presence of phases, respectively. The annealing temperature was varied between 790 and 880 C to optimize processing parameters. Results are given. In brief, an optimum process is reported along with composition of leaded bismuth cuprate superconductor which yields nearly a high T sub c single phase with highly stable superconducting properties
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