scholarly journals Holographic Lifshitz superconductors with Weyl correction

2020 ◽  
Vol 80 (11) ◽  
Author(s):  
Jun-Wang Lu ◽  
Ya-Bo Wu ◽  
Bao-Ping Dong ◽  
Yu Zhang

AbstractAt the probe approximation, we construct a holographic p-wave conductor/superconductor model in the five-dimensional Lifshitz black hole with the Weyl correction via both numerical and analytical methods, and study the effects of the Lifshitz parameter z as well as the Weyl parameter $$\gamma $$ γ on the superconductor model. As we take into account one of the two corrections separately, the increasing z ($$\gamma $$ γ ) inhibits(enhances) the superconductor phase transition. When the two corrections are considered comprehensively, they display the obviously competitive effects on both the critical temperature and the vector condensate. In particular, the promoting effects of the Weyl parameter $$\gamma $$ γ on the critical temperature are obviously suppressed by the increasing Lifshitz parameter. Meanwhile, in the case of $$z<2.35$$ z < 2.35 ($$z>2.35$$ z > 2.35 ), the condensate at lower temperature decreases(increases) with the increasing Weyl parameter $$\gamma $$ γ . What is more, the difference among the condensate with the fixed Weyl parameter($$\gamma =-\frac{6}{100},0,\frac{4}{100}$$ γ = - 6 100 , 0 , 4 100 ) decreases(increases) with the increasing Lifshitz parameter z in the region $$z<2.35$$ z < 2.35 ($$z>2.35$$ z > 2.35 ). Furthermore, the increasing z obviously suppresses the real part of conductivity for all value of the Weyl parameter $$\gamma $$ γ . In addition, the analytical results agree well with the ones from the numerical method.

2020 ◽  
Vol 80 (7) ◽  
Author(s):  
Jun-Wang Lu ◽  
Ya-Bo Wu ◽  
Li-Gong Mi ◽  
Hao Liao ◽  
Bao-Ping Dong

Abstract Via both numerical and analytical methods, we build the holographic s-wave insulator/superconductor model in the five-dimensional AdS soliton with the Horndeski correction in the probe limit and study the effects of Horndeski parameter k on the superconductor model. For the fixed mass squared of the scalar field ($$m^2$$m2), the critical chemical potential $$\mu _c$$μc increases with the larger Horndeski parameter k, which means that the increasing Horndeski correction hinders the superconductor phase transition. Meanwhile, above the critical chemical potential, the obvious pole arises in the low frequency of the imaginal part of conductivity, which signs the appearance of superconducting state. What is more, the energy of quasiparticle excitation decreases with the larger Horndeski correction. Furthermore, the critical exponent of the condensate (charge density) is $$\frac{1}{2}$$12 (1), which is independent of the Horndeski correction. In addition, the analytical results agree well with the numerical results. Subsequently, the conductor/superconductor model with Horndeski correction is analytically realized in the four- and five-dimensional AdS black holes. It is observed that the increasing Horndeski correction decreases the critical temperature and thus hinders the superconductor phase transition, which agrees with the numerical result in the previous works.


2017 ◽  
Vol 26 (11) ◽  
pp. 1750138 ◽  
Author(s):  
Kh. Jafarzade ◽  
J. Sadeghi

In this paper, we take cosmological constant as a thermodynamical pressure and its conjugate quantity as a thermodynamical volume. This expression helps us to investigate the phase transition and holographic heat engine. So, in order to have Van der Waals fluid behavior in Horava–Lifshitz (HL) black hole, we modified the solution of such black hole with some cosmology ansatz. Also from holographic heat engine, we obtain Carnot efficiency for the HL black hole. The phase transition of the system lead us to investigate the stability condition for the corresponding black hole. In that case, we show that the stability exist only in special region of black hole.


2000 ◽  
Vol 15 (25) ◽  
pp. 1589-1595 ◽  
Author(s):  
ZHONG CHAO WU

The constrained instanton method is used to study quantum creation of a vacuum or charged topological black hole. At the WKB level, the relative creation probability is the exponential of a quarter of the sum of the horizon areas associated with the seed instanton. The universe without a black hole has the highest creation probability. The difference between this creation scenario and the Hawking–Page phase transition in the anti-de Sitter background is clarified.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Euro Spallucci ◽  
Anais Smailagic

We study the phases of a Schwarzschild black hole in the Anti-deSitter background geometry. Exploiting fluid/gravity duality, we construct the Maxwell equal area isotherm   in the temperature-entropy plane, in order to eliminate negative heat capacity BHs. The construction we present here is reminiscent of the isobar cut in the pressure-volume plane which eliminates unphysical part of the Van der Walls curves below the critical temperature. Our construction also modifies the Hawking-Page phase transition. Stable BHs are formed at the temperature , while pure radiation persists for . turns out to be below the standard Hawking-Page temperature and there are no unstable BHs as in the usual scenario. Also, we show that, in order to reproduce the correct BH entropy , one has to write a black hole equation of state, that is, , in terms of the geometrical volume .


2017 ◽  
Vol 27 (01) ◽  
pp. 1750175 ◽  
Author(s):  
Z. Sherkatghanad ◽  
B. Mirza ◽  
F. Lalehgani Dezaki

We analytically describe the properties of the s-wave holographic superconductor with the exponential nonlinear electrodynamics in the Lifshitz black hole background in four-dimensions. Employing an assumption the scalar and gauge fields backreact on the background geometry, we calculate the critical temperature as well as the condensation operator. Based on Sturm–Liouville method, we show that the critical temperature decreases with increasing exponential nonlinear electrodynamics and Lifshitz dynamical exponent, [Formula: see text], indicating that condensation becomes difficult. Also we find that the effects of backreaction has a more important role on the critical temperature and condensation operator in small values of Lifshitz dynamical exponent, while [Formula: see text] is around one. In addition, the properties of the upper critical magnetic field in Lifshitz black hole background using Sturm–Liouville approach is investigated to describe the phase diagram of the corresponding holographic superconductor in the probe limit. We observe that the critical magnetic field decreases with increasing Lifshitz dynamical exponent, [Formula: see text], and it goes to zero at critical temperature, independent of the Lifshitz dynamical exponent, [Formula: see text].


2018 ◽  
Vol 249 ◽  
pp. 01008
Author(s):  
Atchara Punya Jaroenjittichai ◽  
Yongyut Laosiritaworn

In this work, Monte Carlo simulation was employed to investigate the competitive effect of non-magnetic defects and the thickness on the ferromagnetic behavior of Ising spins in a reduced geometry, i.e. thin-films. The magnetic properties were investigated as functions of temperature, defect concentration, and films’ thickness, especially in the ferromagnetic phase transition region. The finite size scaling was performed via the fourth order cumulant of the magnetization to extract the critical temperatures. From the results, the extracted critical temperatures agree well with previous theoretical investigation, where applicable. With increasing concentration of the nonmagnetic defects, the Ising phase-transition-point slightly shifts towards lower temperature, while the increase of films thickness enhances the critical temperature value. Being confirmed by the main-effect-plot analysis, the increase in thickness has much greater influences on the critical temperature than that of the defect concentration, which could be described in term of the average ferromagnetic interaction spin. As the role of the defect is negligence in the range of considered defect concentration (up to ten percent), it therefore suggests that the preparation of ferromagnetic films can be done in normal operating condition where defects usually occur. It may be not economically worth to aim for the perfectly smooth films when the associated application operates at temperatures away from the critical point.


2018 ◽  
Vol 33 (33) ◽  
pp. 1850193 ◽  
Author(s):  
Tanay K. Dey

We study the thermodynamics of AdS–Schwarzschild black hole in the presence of an external string cloud. We observe that, at any temperature, the black hole configuration is stable with nonzero entropy. We further notice that when the value of the curvature constant equals to one, if the string cloud density has less than a critical value, within a certain range of temperature three black holes configurations exist. One of these black holes is unstable and other two are stable. At a critical temperature, a transition between these two stable black holes takes place which leads us to conclude that the bound state of quark and antiquark pairs may not exist. By studying the corresponding dual gauge theory, we confirm the instability of the bound state of quark and antiquark pair in the dual gauge theory.


1999 ◽  
Vol 14 (05) ◽  
pp. 379-385 ◽  
Author(s):  
KARL LANDSTEINER

We compute the O(α′3) corrections to the AdS5 black hole metric in type IIB string theory. Contrary to previous work in this direction we keep the black hole radius finite. Thus the topology of the boundary is S3×S1. We find the corrections to the free energy and the critical temperature of the phase transition.


Author(s):  
Scott Tremaine

Abstract The supermassive black holes found at the centres of galaxies are often surrounded by dense star clusters. The ages of these clusters are generally longer than the resonant-relaxation time and shorter than the two-body relaxation time over a wide range of radii. We explore the thermodynamic equilibria of such clusters using a simple self-similar model. We find that the cluster exhibits a phase transition between a high-temperature spherical equilibrium and a low-temperature equilibrium in which the stars are on high-eccentricity orbits with nearly the same orientation. In the absence of relativistic precession, the spherical equilibrium is metastable below the critical temperature and the phase transition is first-order. When relativistic effects are important, the spherical equilibrium is linearly unstable below the critical temperature and the phase transition is continuous. A similar phase transition has recently been found in a model cluster composed of stars with a single semimajor axis. The presence of the same phenomenon in two quite different cluster models suggests that lopsided equilibria may form naturally in a wide variety of black-hole star clusters.


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