320 research outputs found
Clapeyron equation and phase equilibrium properties in higher dimensional charged topological dilaton AdS black holes with a nonlinear source
Using Maxwell's equal area law, we discuss the phase transition of higher
dimensional charged topological dilaton AdS black holes with a nonlinear
source. The coexisting region of the two phases is found and we depict the
coexistence region in diagrams. The two-phase equilibrium curves in
diagrams are plotted, and we take the first order approximation of volume
in the calculation. To better compare with a general thermodynamic system, the
Clapeyron equation is derived for higher dimensional charged topological black
hole with a nonlinear source. The latent heat of isothermal phase transition is
investigated. We also study the effect of the parameters of the black hole on
the region of two-phases coexistence. The results show that the black hole may
go through a small-large phase transition similar to those of usual non-gravity
thermodynamic systems.Comment: 21 pages,25 figures. published version in EPJC. arXiv admin note:
substantial text overlap with arXiv:1411.7202; text overlap with
arXiv:1506.01786, arXiv:hep-th/0605042 by other author
Hawking-Page Phase Transition of the four-dimensional de-Sitter Spacetime with non-linear source
The interplay between a dS black hole and cosmological horizons introduces
distinctive thermodynamic behavior in a dS spacetime (for example the
well-known upper bounds of mass and entropy in Class. Quant. Grav. 37 (2020)
5). Based on this point, we present the Hawking-Page (HP) phase transition of
the four-dimensional dS spacetime with non-linear charge correction when the
effective pressure is fixed, and analyze the effects of different effective
pressures and non-linear charge corrections on HP phase transition. The
evolution of this dS spacetime undergoing the HP phase transition is also
investigated. We find that the existent curve of HP phase transition is a
closed one with two different branches. That means there exist the upper bounds
of the HP temperature and HP pressure, which is completely distinguished with
that in AdS spacetime. And with the decreasing of the distance between two
horizons, the dS spacetime at the coexistent curve of HP phase transition is
going along with different branches. Furthermore we also explore the influence
of charge and non-linear charge correction on the coexistent curve
Unconventional Superconducting Symmetry in a Checkerboard Antiferromagnet
We use a renormalized mean field theory to study the Gutzwiller projected BCS
states of the extended Hubbard model in the large limit, or the
--- model on a two-dimensional checkerboard lattice. At small
, the frustration due to the diagonal terms of and does not
alter the -wave pairing symmetry, and the negative (positive)
enhances (suppresses) the pairing order parameter. At large , the
ground state has an extended s-wave symmetry. At the intermediate , the
ground state is or -wave with time reversal symmetry broken.Comment: 6 pages, 6 figure
Photon orbits and phase transition for Non-Linear charged Anti-de Sitter black holes
In this work, we investigate the relationship between the photon sphere
radius and the first-order phase transition for the charged EPYM AdS black
hole. Through the analysis, we find with a certain condition there exist the
non-monotonic behaviors between the photon sphere radius, the impact parameter,
the non-linear YM charge parameter, temperature, and pressure. And both the
changes of photon sphere radius and impact parameter before and after phase
transition can be regarded as the order parameter, their critical exponents
near the critical point are equal to the same value , just like the
ordinary thermal systems. These indicate that there maybe exists a universal
relationship of gravity nearby the critical point for a black hole
thermodynamical system. Furthermore, the effect of impact parameter on the
deflect angle is also investigated
Charge Ordered RVB States in the Doped Cuprates
We study charge ordered d-wave resonating valence bond states (dRVB) in the
doped cuprates, and estimate the energies of these states in a generalized model by using a renormalized mean field theory. The long range Coulomb
potential tends to modulate the charge density in favor of the charge ordered
RVB state. The possible relevance to the recently observed
checkerboard patterns in tunnelling conductance in high cuprates is
discussed.Comment: 4 pages, 4 figures, 3 table
Experimental high-intensity three-photon entangled source
We experimentally realize a high-intensity three-photon
Greenberger-Horne-Zeilinger (GHZ) entanglement source directly following the
proposal by Rarity and Tapster [J. G. Rarity and P. R. Tapster, Phys. Rev. A
59, R35 (1999)]. The threefold coincidence rate can be more than 200 Hz with a
fidelity of 0.811, and the intensity can be further improved with moderate
fidelity degradation. The GHZ entanglement is characterized by testing the
Bell-Mermin inequality and using an entanglement witness operator. To optimize
the polarization-entangled source, we theoretically analyze the relationship
between the mean photon number of the single-photon source and the probability
of parametric down-conversion.Comment: 4 pages, 4 figure
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