13,741 research outputs found
P-Wave Holographic Insulator/Superconductor Phase Transition
Using a five dimensional AdS soliton in an Einstein-Yang-Mills theory with
SU(2) gauge group we study p-wave holographic insulator/superconductor phase
transition. To explore the phase structure of the model we consider the system
in the probe limit as well as fully back reacted solutions. We will also study
zero temperature limit of the p-wave holographic superconductor in four
dimensions.Comment: Latex,18 pages,7 figures, v2: Typos correction, v3: minor changes
added, and clarifications mad
A mechanical behavior law for the numerical simulation of the mushy zone in welding
The aim of this work is to propose a mechanical behavior law dedicated to the mushy zone located between the solid phase and the weld pool in welding. The objective is to take into account of the influence of the mushy zone in the simulation of welding in order to improve the computation of induced effects such as residual stresses
Continuous Monitoring of Rabi Oscillations in a Josephson Flux Qubit
Under resonant irradiation, a quantum system can undergo coherent (Rabi)
oscillations in time. We report evidence for such oscillations in a
_continuously_ observed three-Josephson-junction flux qubit, coupled to a
high-quality tank circuit tuned to the Rabi frequency. In addition to
simplicity, this method of_Rabi spectroscopy_ enabled a long coherence time of
about 2.5 microseconds, corresponding to an effective qubit quality factor
\~7000.Comment: REVTeX4, 4pp., 4 EPS figure files. v3: changed title, fixed typos;
final, to appear in PR
Fermions in non-relativistic AdS/CFT correspondence
We extend the non-relativistic AdS/CFT correspondence to the fermionic
fields. In particular we study the two point function of a fermionic operator
in non-relativistic CFTs by making use of a massive fermion propagating in
geometries with Schrodinger group isometry. Although the boundary of the
geometries with Schrodinger group isometry differ from that in AdS geometries
where the dictionary of AdS/CFT is established, using the general procedure of
AdS/CFT correspondence, we see that the resultant two point function has the
expected form for fermionic operators in non-relativistic CFTs, though a
non-trivial regularization may be needed.Comment: 12 pages,Latex file; V2: typos corrected, refs adde
Quantum Field Theory of Forward Rates with Stochastic Volatility
In a recent formulation of a quantum field theory of forward rates, the
volatility of the forward rates was taken to be deterministic. The field theory
of the forward rates is generalized to the case of stochastic volatility. Two
cases are analyzed, firstly when volatility is taken to be a function of the
forward rates, and secondly when volatility is taken to be an independent
quantum field. Since volatiltiy is a positive valued quantum field, the full
theory turns out to be an interacting nonlinear quantum field theory in two
dimensions. The state space and Hamiltonian for the interacting theory are
obtained, and shown to have a nontrivial structure due to the manifold moving
with a constant velocity. The no arbitrage condition is reformulated in terms
of the Hamiltonian of the system, and then exactly solved for the nonlinear
interacting case.Comment: 7 Figure
Non-Equilibrium Quasiclassical Theory for Josephson Structures
We present a non-equilibrium quasiclassical formalism suitable for studying
linear response ac properties of Josephson junctions. The non-equilibrium
self-consistency equations are satisfied, to very good accuracy, already in
zeroth iteration. We use the formalism to study ac Josephson effect in a
ballistic superconducting point contact. The real and imaginary parts of the ac
linear conductance are calculated both analytically (at low frequencies) and
numerically (at arbitrary frequency). They show strong temperature, frequency,
and phase dependence. Many anomalous properties appear near phi = pi. We
ascribe them to the presence of zero energy bound states.Comment: 11 pages, 9 figures, Final version to appear in PR
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