标题： 有限剪切应变下均匀全息固体的力学稳定性 显示英文标题

标题： Mechanical stability of homogeneous holographic solids under finite shear strain

摘要： 我们研究了有限温度下具有背景剪切应变的全息均匀固体（HHS）的线性稳定性，通过超出流体力学极限的大规模准正则模分析方法。 我们发现，机械失稳可能由声速的复数值（梯度失稳）或负扩散常数引起。 令人惊讶的是，最简单的HHS模型对于任意大的背景应变值都表现出线性稳定性。 对于更复杂的HHS，扩散失稳的发生总是先于梯度失稳，而梯度失稳仅在背景剪切应变超过某一临界值时成为主要的破坏过程。 最后，我们观察到两种失稳的临界应变在低温下趋于接近。 最后，我们通过展示HHS的相图得出结论，该相图以温度和背景剪切应变为函数，显示出与存在背景超流速度的超流体物理的有趣相似性。 显示英文摘要

摘要： We study the linear stability of holographic homogeneous solids (HHS) at finite temperature and in presence of a background shear strain by means of a large scale quasi-normal mode analysis which extends beyond the hydrodynamic limit. We find that mechanical instability can arise either as a result of a complex speed of sound -- gradient instability -- or of a negative diffusion constant. Surprisingly, the simplest HHS models are linearly stable for arbitrarily large values of the background strain. For more complex HHS, the onset of the diffusive instability always precedes that of the gradient instability, which becomes the dominant destabilizing process only above a critical value of the background shear strain. Finally, we observe that the critical strains for the two instabilities approach each other at low temperatures. We conclude by presenting a phase diagram for HHS as a function of temperature and background shear strain which shows interesting similarities with the physics of superfluids in presence of background superfluid velocity.