Light-cone effect and supersonic correlations in one-and two-dimensional bosonic superfluids
Light-cone effect and supersonic correlations in one-and two-dimensional bosonic superfluids
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DOI：
10.1103/physreva.89.031602
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发表时间：
2014-03-27
影响因子：
2.9
通讯作者：
Fabrizio, Michele
中科院分区：
文献类型：
--
作者：
Carleo, Giuseppe;Becca, Federico;Fabrizio, Michele
用含时变分蒙特卡罗模拟方法研究了相互作用强度熄灭后Bose-Hubbard模型中密度-密度关联的扩展。它提供了前所未有的长传播时间和比1更高的维度。在一维和二维中，我们发现了弹道光锥扩散的关联，并提取了超流区光锥速度的精确值。我们发现，关联的传播一般是超音速的，光锥传播速度快于声模，但慢于密度激发的最大群速度，除了在Mott跃迁，所有特征速度都是相等的。此外，我们还证明了在二维空间中，相关扩展是高度各向异性的，并且呈现出非平凡的干扰效应。
We study the spreading of density-density correlations in Bose-Hubbard models after a quench of the interaction strength, using time-dependent variational Monte Carlo simulations. It gives access to unprecedented long propagation times and to dimensions higher than one. In both one and two dimensions, we find ballistic light-cone spreading of correlations and extract accurate values of the light-cone velocity in the superfluid regime. We show that the spreading of correlations is generally supersonic, with a light-cone propagating faster than sound modes but slower than the maximum group velocity of density excitations, except at the Mott transition, where all the characteristic velocities are equal. Further, we show that in two dimensions the correlation spreading is highly anisotropic and presents nontrivial interference effects.