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arXiv 1601.06167cond-mat.stat-mechcond-mat.str-el
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一维无自旋费米子相互作用系统的磁通猝灭

Flux quench in a system of interacting spinless fermions in one dimension

Yuya O. Nakagawa, Grégoire Misguich, Masaki Oshikawa

摘要:

我们研究了一维无自旋费米子模型(相当于XXZ自旋链)中的量子猝灭,其中一个磁通量突然被切断。该猝灭等效于施加电场的脉冲,并且因此产生初始粒子电流。该电流在晶格和相互作用的存在下不是守恒量,并且我们使用无限时间演化块抽取方法数值研究了其在淬火后的时间演化。对于排斥相互作用或大的初始通量,我们发现振荡是由费米海深处的激发。在很长的时间里,我们观察到电流在无间隙的情况下保持不为零,而在有间隙的情况下,电流衰减到零。虽然线性响应理论(有效的弱通量)预测相同的长时间限制的排斥和吸引力的相互作用(与零温度德鲁德重量的关系)的电流,较大的非线性观察排斥相互作用的情况下相比,吸引力的情况下。

英文摘要:

We study a quantum quench in a one-dimensional spinless fermion model (equivalent to the XXZ spin chain), where a magnetic flux is suddenly switched off. This quench is equivalent to imposing a pulse of electric field and therefore generates an initial particle current. This current is not a conserved quantity in presence of a lattice and interactions and we investigate numerically its time-evolution after the quench, using the infinite time-evolving block decimation method. For repulsive interactions or large initial flux, we find oscillations that are governed by excitations deep inside the Fermi sea. At long times we observe that the current remains non-vanishing in the gapless cases, whereas it decays to zero in the gapped cases. Although the linear response theory (valid for a weak flux) predicts the same long-time limit of the current for repulsive and attractive interactions (relation with the zero-temperature Drude weight), larger nonlinearities are observed in the case of repulsive interactions compared with that of the attractive case.

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。

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