| Gauge/gravity correspondence creates a new links between quantum theory and grav-ity.It claims that the d dimensions strongly coupled quantum many-body system has a d+1 classical gravitational dual.Gauge/gravity correspondence provide a new approach to study strongly coupled systems.Based on the s-wave holographic superconductor mod-el,some of the interesting phase transitions in the system with multiple orders has been a hearted discussion.In this thesis,I’ll introduce the methods and main results of the holographic superconductivity with multiple orders using my research work as examples.In this article,we explore the holographic superconductor model with two s-wave orders from(4+1)dimensional Einstein-Gauss-Bonnet gravity in the probe limit.At different values of the Gauss-Bonnet coefficientα,we study the influence of tuning the mass and charge parameters of the bulk scalar field on the free energy curve of condensed solution with single s-wave order.It is found that the free energy curve of condensed solution with single s-wave order along with either of the two parameters can be changed.However,if only one of the two parameters is changed,the free energy curves of the resulting different solutions will not intersect with each other.And we compare the different influences of tuning the two different parameters on the free energy curve while the changes of the critical temperature are the same.Based on the above results,if the appropriate parameter values are selected,we find that the two free energy curves of different s-wave order can have one or two intersections points.We can find two typical phase transition behaviors of the s+s coexisting phase in the course of our study,including the reentrant phase transition near the Chern-Simons limitα=0.25.We also give a heuristic explain to the nontrivial behavior of the T_c-αcurves near the Chern-Simons limit,which might have relation with the origin of the special reentrant behavior. |
