204,982 research outputs found
Quantum-disordered slave-boson theory of underdoped cuprates
We study the stability of the spin gap phase in the U(1) slave-boson theory
of the t-J model in connection to the underdoped cuprates. We approach the spin
gap phase from the superconducting state and consider the quantum phase
transition of the slave-bosons at zero temperature by introducing vortices in
the boson superfluid. At finite temperatures, the properties of the bosons are
different from those of the strange metal phase and lead to modified gauge
field fluctuations. As a result, the spin gap phase can be stabilized in the
quantum critical and quantum disordered regime of the boson system. We also
show that the regime of quantum disordered bosons with the paired fermions can
be regarded as the strong coupling version of the recently proposed nodal
liquid theory.Comment: 5 pages, Replaced by the published versio
On Types of Elliptic Pseudoprimes
We generalize the notions of elliptic pseudoprimes and elliptic Carmichael
numbers introduced by Silverman to analogues of Euler-Jacobi and strong
pseudoprimes. We investigate the relationships among Euler Elliptic Carmichael
numbers , strong elliptic Carmichael numbers, products of anomalous primes and
elliptic Korselt numbers of Type I: The former two of these are introduced in
this paper, and the latter two of these were introduced by Mazur (1973) and
Silverman (2012) respectively. In particular, we expand upon a previous work of
Babinkostova et al. by proving a conjecture about the density of certain
elliptic Korselt numbers of Type I that are products of anomalous primes.Comment: Revised for publication. 33 page
Pertinent Dirac structure for QCD sum rules of meson-baryon coupling constants
Using general baryon interpolating fields for
without derivative, we study QCD sum rules for meson-baryon couplings and their
dependence on Dirac structures for the two-point correlation function with a
meson i\int d^4x e^{iqx} \bra 0|{\rm T}[J_B(x)\bar{J}_B(0)] |{\cal M}(p)\ket.
Three distinct Dirac structures are compared: ,
i\gamma_5\fslash{p}, and structures.
From the dependence of the OPE on general baryon interpolating fields, we
propose criteria for choosing an appropriate Dirac structure for the coupling
sum rules. The sum rules satisfy the
criteria while the sum rules beyond the chiral limit do not. For
the i\gamma_5\fslash{p} sum rules, the large continuum contributions prohibit
reliable prediction for the couplings. Thus, the structure seems pertinent for realistic predictions. In the SU(3) limit,
we identify the OPE terms responsible for the ratio. We then study the
dependence of the ratio on the baryon interpolating fields. We conclude the
ratio for appropriate choice of the interpolating fields.Comment: To be published in Phys.Rev.C ; 21 pages,8 figures, revtex ;
references are adde
Symmetric Subgroups of Gauged Supergravities and AdS String Theory Vertex Operators
We show how the gauge symmetry representations of the massless particle
content of gauged supergravities that arise in the AdS/CFT correspondences can
be derived from symmetric subgroups to be carried by string theory vertex
operators in these compactified models, although an explicit vertex operator
construction of IIB string and M theories on AdSxS remains elusive. Our
symmetry mechanism parallels the construction of representations of the Monster
group and affine algebras in terms of twisted conformal field theories, and may
serve as a guide to the perturbative description of the IIB string on AdSxS.Comment: 9 pages, LaTe
Epitaxial growth of gallium arsenide with ammonium halides as transporting agents
Epitaxial growth of gallium arsenide with ammonium halides as transporting agent
High-performance Schottky diodes endure high temperatures
Fabrication process and aluminum/GaAs (gallium arsenide) coupling are used to produce Schottky diodes that have high cutoff frequencies and can withstand operating temperatures in excess of 500 C
Influence of magnetic viscosity on domain wall dynamics under spin-polarized currents
We present a theoretical study of the influence of magnetic viscosity on
current-driven domain wall dynamics. In particular we examine how domain wall
depinning transitions, driven by thermal activation, are influenced by the
adiabatic and nonadiabatic spin-torques. We find the Arrhenius law that
describes the transition rate for activation over a single energy barrier
remains applicable under currents but with a current-dependent barrier height.
We show that the effective energy barrier is dominated by a linear current
dependence under usual experimental conditions, with a variation that depends
only on the nonadiabatic spin torque coefficient beta.Comment: 8 pages, 4 figure
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