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Holographic incoherent transport in Einstein-Maxwell-Dilaton Gravity

Zhenhua Zhou; Yi Ling; Jian-Pin WuSubjects: Physics >> Nuclear Physics

Recent progress in holographic approach makes it more transparent that each conductivity can be decomposed into the coherent contribution due to momentum relaxation and the incoherent contribution due to intrinsic current relaxation. In this paper we investigate this decomposition in the framework of Einstein-Maxwell-Dilaton theory. We derive the perturbation equations which are decoupled for a large class of background solutions, and then obtain the analytic results of conductivity with slow momentum relaxation in low frequency approximation, which is consistent with the known results from memory matrix techniques. |

A novel insulator by holographic Q-lattices

Yi Ling; Peng Liu; Jian-Pin WuSubjects: Physics >> Nuclear Physics

We construct a bulk geometry with Q-lattice structure, which is implemented by two gauge fields and a coupling between the lattice and the Maxwell field. This gravity dual model can describe a novel insulator which exhibits some key features analogous to Mott insulator. In particular, a hard gap in insulating phase as well as vanishing DC conductivity can be simultaneously achieved. In addition, we discuss the non-Drude behavior of the optical conductivity in low frequency region in insulating phase, which exhibits some novel characteristics different from ordinary Mott insulator. |

DC and Hall conductivity in holographic massive Einstein-Maxwell-Dilaton gravity

Zhenhua Zhou; Jian-Pin Wu; Yi LingSubjects: Physics >> Nuclear Physics

We investigate the holographic DC and Hall conductivity in massive Einstein-Maxwell-Dilaton (EMD) gravity. Two special EMD backgrounds are considered explicitly. One is dyonic Reissner-Nordstro╩-AdS (RN-AdS) geometry and the other one is hyperscaling violation AdS (HV-AdS) geometry. We find that the linear-T resistivity and quadratic-T inverse Hall angle can be simultaneously achieved in HV-AdS models, providing a hint to construct holographic models confronting with the experimental data of strange metal in future. |

Holographic Entanglement Entropy Close to Quantum Phase Transitions

Yi Ling; Peng Liu; Chao Niu; Jian-Pin Wu; Zhuo-Yu XianSubjects: Physics >> Nuclear Physics

We investigate the holographic entanglement entropy (HEE) of a strip geometry in four dimensional Q-lattice backgrounds, which exhibit metal-insulator transitions in the dual field theory. Remarkably, we find that the HEE always displays a peak in the vicinity of the quantum critical points. Our model provides the first direct evidence that the HEE can be used to characterize the quantum phase transition (QPT). We also conjecture that the maximization behavior of HEE at quantum critical points would be universal in general holographic models. |

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