论文标题
共形秩序的命运
The fate of the conformal order
论文作者
论文摘要
我们使用全息信函来研究在$ {\ mathbb r}^{2,1} $中以自发损坏的全局$ z_2 $对称的阶段的传输。渐近$ ADS_4 $的繁殖剂中的双黑晶体具有“头发” - 破碎对称性的顺序参数的冷凝物。这种头发影响黑麸皮的流体动力学和非流动力的准模式。尽管如此，共形秩序的剪切粘度是通用的，散装粘度消失了，声波的速度为$ C_S^2 = \ frac 12 $。我们计算非流动力模式的低洼光谱。我们确定与$ z_2 $订单参数与正数零件的波动相关的准模式。该模式在频谱中的存在使全息形成顺式顺序在扰动上不稳定。相应地，双黑晶体违反了相关的稳定性猜想。
We use holographic correspondence to study transport of the conformal plasma in ${\mathbb R}^{2,1}$ in a phase with a spontaneously broken global $Z_2$ symmetry. The dual black branes in a Poincare patch of asymptotically $AdS_4$ have "hair" -- a condensate of the order parameter for the broken symmetry. This hair affects both the hydrodynamic and the nonhydrodynamic quasinormal modes of the black branes. Nonetheless, the shear viscosity of the conformal order is universal, the bulk viscosity vanishes and the speed of the sound waves is $c_s^2=\frac 12$. We compute the low-lying spectrum of the non-hydrodynamic modes. We identify a quasinormal mode associated with the fluctuations of the $Z_2$ order parameter with the positive imaginary part. The presence of this mode in the spectrum renders the holographic conformal order perturbatively unstable. Correspondingly, the dual black branes violate the correlated stability conjecture.
