Landau不稳定性与孤子形成
Landau Instability and soliton formation
AI总结：
本文利用全息对偶模拟超流体Landau不稳定性的演化，发现系统最终稳定为速度低于临界值的均匀态，并揭示了通过孤子自发成核降低超流体速度的机制。
摘要：
考虑在有限温度$T$下，超流体以速度$v$相对于热浴或其正常分量运动。根据Landau的论证，存在一个临界速度$v_c(T)$，超过该速度后激发可以自发产生，系统变得不稳定。确定这种不稳定性导致的最终状态一直是一个突出的开放问题。我们使用全息对偶对从初始不稳定状态演化的动力学过程进行了模拟，发现系统最终稳定在一个最终速度低于临界速度的均匀超流体状态。动力学演化过程似乎高度混沌，表现出瞬态湍流。尽管如此，我们仍能从模拟中识别出超流体速度降低的普遍物理机制，即通过孤子的自发成核。我们还推导出一个简单的解析公式，将最终速度与演化过程中成核的孤子数量联系起来。
英文摘要：
Consider at a finite temperature $T$ a superfluid moving with a velocity $v$ relative to the thermal bath or its normal component. From Landau's argument there exists a critical $v_c (T)$ beyond which excitations can be spontaneously generated and the system becomes unstable. Identifying the final state induced by such an instability has been an outstanding open question. Using holographic duality we perform dynamical simulations of evolutions from initial unstable states, and find that the system settles to a homogenous superfluid state with a final velocity below the critical velocity. The dynamical evolution process appears to be highly chaotic, exhibiting transient turbulence. Nevertheless we are able to identify from the simulations a universal physical mechanism for the reduction of superfluid velocity, in terms of spontaneous nucleation of solitons. We also derive a simple analytic formula which relates the final velocity to the number of solitons nucleated during the evolution.
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。
