1,573 research outputs found
Characteristic length of a Holographic Superconductor with -wave gap
After the discovery of the -wave and -wave holographic superconductors,
holographic models of -wave superconductor have also been constructed
recently. We study analytically the perturbation of the dual gravity theory to
calculate the superconducting coherence length of the -wave
holographic superconductor near the superconducting phase transition point. The
superconducting coherence length divergents as near
the critical temperature . We also obtain the magnetic penetration depth
by adding a small external homogeneous magnetic
field. The results agree with the -wave and -wave models, which are also
the same as the Ginzburg-Landau theory.Comment: last version, 10 pages, accepted by PR
Development of a Performance Calculation Program for Solar Domestic Hot Water Systems with Improved Prediction of Thermal Stratification
d-wave Holographic Superconductor Vortex Lattice and Non-Abelian Holographic Superconductor Droplet
A d-wave holographic superconductor is studied under a constant magnetic
field by perturbation method, we obtain both droplet and triangular vortex
lattice solution. The results are the same as the s-wave holographic
superconductor. The non-Abelian holographic superconductor with -wave
background is also studied under magnetic field, unlike the d-wave and s-wave
models, we find that the non-Abelian model has only droplet solution.Comment: Version2, 12 pages,2 figures. Accepted by PR
Bulk and Surface Critical Behaviors of quantum Heisenberg antiferromagnet on a two-dimensional coupled diagonal ladders
Using Quantum Monte Carlo simulations, we study the spin-1/2 Heisenberg model
on a two-dimensional lattice formed by coupling diagonal ladders. The model
hosts an antiferromagnetic N\'eel phase, a rung singlet product phase, and a
topological none trivial Haldane phase, separated by two quantum phase
transitions. We show that the two quantum critical points are all in the
three-dimensional O(3) universality class. The properties of the two gapped
phases, including the finite-size behavior of the string orders in the Haldane
phase, are studied. We show that the surface formed by the ladders ends is
gapless, while the surface exposed along the ladders is gapful, in the Haldane
phase.
Conversely, in the gapped rung singlet phase, the former surface is gapped,
and the latter is gapless. We demonstrate that, although mechanisms of the two
gapless modes are different, nonordinary surface critical behaviors are
realized at both critical points on the gapless surfaces exposed by simply
cutting bonds without fine-tuning the surface coupling required to reach a
multicritical point in classical models. We also show that, on the gapped
surfaces, the surface critical behaviors are in the ordinary class.Comment: 12 pages, 8 figure
Extraordinary surface critical behavior induced by symmetry-protected topological state of a two-dimensional quantum magnet
Using Quantum Monte Carlo simulations, we study spin-1/2 diagonal ladders
coupled by ferromagnetic Heisenberg interactions. The model can also be viewed
as usual ladders with ferromagnetic rung couplings coupled by antiferromagnetic
diagonal couplings. We find that the model hosts a striped magnetic ordered
phase and two topological nontrivial Haldane phases, separated by two quantum
critical points. We show that the two quantum critical points are all in the
three-dimensional O(3) universality class irrelevant to the topological
properties of the Haldane phases. The properties of the surface formed by
ladder ends in the two Haldane phases are studied. We find that the surface
states are both gapless due to the symmetry-protected topological bulk states.
We further demonstrate that extraordinary surface critical behaviors are
realized at both critical points on such gapless surfaces without enhancing the
surface coupling. Notably, the surface is not expected to be ordered in the
three-dimensional classical O(3) critical point, suggesting that the
topological properties of the Haldane phases are responsible for such surface
critical behavior.Comment: 10 pages, 6 figure
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