Thermoelectric transport in disordered metals without quasiparticles: The Sachdev-Ye-Kitaev models and holography
Thermoelectric transport in disordered metals without quasiparticles: The Sachdev-Ye-Kitaev models and holography
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DOI：
10.1103/physrevb.95.155131
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发表时间：
2017-04-18
影响因子：
3.7
通讯作者：
Sachdev, Subir
中科院分区：
文献类型：
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作者：
Davison, Richard A.;Fu, Wenbo;Sachdev, Subir
我们计算了具有守恒费米子数Q的费米子的Sachdev-Ye-Kitaev(SYK)模型的热力学性质。我们将以前提出的Schwarzian有效作用推广到包括相场，这描述了低温能量和Q的涨落。我们得到了无准粒子激发的无序金属态的SYK模型的高维推广，并推导了它们的热电输运系数。我们还考察了从ADS(4)或ADS(5)到ADS(2)×R-2或ADS(2)×R-3近视界几何的黑膜几何上的爱因斯坦-麦克斯韦轴子理论的相应性质。它们提供了没有动量守恒的非准粒子金属状态的全息描述。我们在SYK模型和全息模型的低温输运和热力学之间找到了精确的匹配。在这两个模型中，塞贝克输运系数恰好等于熵的Q导数。对于SYK模型，由蝴蝶速度和Lyapunov速率表征的量子混沌普遍决定热扩散率，而不是电荷扩散率。
We compute the thermodynamic properties of the Sachdev-Ye-Kitaev (SYK) models of fermions with a conserved fermion number Q. We extend a previously proposed Schwarzian effective action to include a phase field, and this describes the low-temperature energy and Q fluctuations. We obtain higher-dimensional generalizations of the SYK models which display disordered metallic states without quasiparticle excitations, and we deduce their thermoelectric transport coefficients. We also examine the corresponding properties of Einstein-Maxwell-axion theories on black brane geometries which interpolate from either AdS(4) or AdS(5) to an AdS(2) x R-2 or AdS(2) x R-3 near-horizon geometry. These provide holographic descriptions of nonquasiparticle metallic states without momentum conservation. We find a precise match between low-temperature transport and thermodynamics of the SYK and holographic models. In both models, the Seebeck transport coefficient is exactly equal to the Q derivative of the entropy. For the SYK models, quantum chaos, as characterized by the butterfly velocity and the Lyapunov rate, universally determines the thermal diffusivity, but not the charge diffusivity.