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arXiv · 1410.6761

Holographic Superconductor on Q-lattice

Yi Ling·Peng Liu·Chao Niu·Jian-Pin Wu·Zhuo-Yu Xian
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Abstract

We construct the simplest gravitational dual model of a superconductor on Q-lattices. We analyze the condition for the existence of a critical temperature at which the charged scalar field will condense. In contrast to the holographic superconductor on ionic lattices, the presence of Q-lattices will suppress the condensate of the scalar field and lower the critical temperature. In particular, when the Q-lattice background is dual to a deep insulating phase, the condensation would never occur for some small charges. Furthermore, we numerically compute the optical conductivity in the superconducting regime. It turns out that the presence of Q-lattice does not remove the pole in the imaginary part of the conductivity, ensuring the appearance of a delta function in the real part. We also evaluate the gap which in general depends on the charge of the scalar field as well as the Q-lattice parameters. Nevertheless, when the charge of the scalar field is relatively large and approaches the probe limit, the gap becomes universal with $ω_g \simeq 9T_c$ which is consistent with the result for conventional holographic superconductors.

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Yi Ling, Peng Liu, Chao Niu, Jian-Pin Wu, Zhuo-Yu Xian. 2015-02-15. Holographic Superconductor on Q-lattice. https://doi.org/10.1007/jhep02(2015)059

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