arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2008.02289hep-thcond-mat.quant-gascond-mat.str-elcond-mat.supr-conhep-ph
收藏

冷全息超流体中的非零正常密度

Non-vanishing normal density in cold holographic superfluids

Blaise Goutéraux, Eric Mefford

摘要:

用两种流体流动的流体力学模型很好地描述了具有超流性的$d+1$维系统的低能和有限温度激发。在量子临界点附近,系统中的热力学和输运预计将由临界指数和远离量子临界点的不相关变形谱控制。在这里,使用规范重力对偶性,我们提出的热力学和电荷输运系数在一阶流体动力学导数展开的临界指数的低温依赖性。将特别注意的行为的正常流的电荷密度的系统与紧急红外共形和Lifshitz对称性,参数化的Lifshitz动力学指数$z>1$。当$1\leq z<d+2$时,我们恢复($z=1$)并推广($z>1$)以前用相对论有效场论技术得到的结果。相反,当$z>d+2$,我们表明,正常的电荷密度在零温度下变得不为零。一个扩展的附录概括了这些结果违反超标度系统以及广义光子质量的系统。我们的研究结果澄清了以前的工作在全息文献和最近的实验测量的铜氧化物超导体的超流密度相关。

英文摘要:

The low energy and finite temperature excitations of a $d+1$-dimensional system exhibiting superfluidity are well described by a hydrodynamic model with two fluid flows: a normal flow and a superfluid flow. In the vicinity of a quantum critical point, thermodynamics and transport in the system are expected to be controlled by the critical exponents and by the spectrum of irrelevant deformations away from the quantum critical point. Here, using gauge-gravity duality, we present the low temperature dependence of thermodynamic and charge transport coefficients at first order in the hydrodynamic derivative expansion in terms of the critical exponents. Special attention will be paid to the behavior of the charge density of the normal flow in systems with emergent infrared conformal and Lifshitz symmetries, parameterized by a Lifshitz dynamical exponent $z>1$. When $1\leq z<d+2$, we recover ($z=1$) and extend ($z>1$) previous results obtained by relativistic effective field theory techniques. Instead, when $z>d+2$, we show that the normal charge density becomes non-vanishing at zero temperature. An extended appendix generalizes these results to systems that violate hyperscaling as well as systems with generalized photon masses. Our results clarify previous work in the holographic literature and have relevance to recent experimental measurements of the superfluid density on cuprate superconductors.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑