Anomalous Spin-Charge Separation in a Driven Hubbard System.
Anomalous Spin-Charge Separation in a Driven Hubbard System.
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DOI：
10.1103/physrevlett.125.195301
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发表时间：
2020-05
影响因子：
8.6
通讯作者：
Hongmin Gao;J. Coulthard;D. Jaksch;J. Mur-Petit
中科院分区：
文献类型：
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作者：
Hongmin Gao;J. Coulthard;D. Jaksch;J. Mur-Petit
自旋-电荷分离（SCS）是低维量子系统中强相关性的显著表现，费米子分裂成以不同速度运动的独立自旋和电荷激发。在这里，我们证明了周期性驱动能够在接近半填充的Hubbard系统中控制SCS。在一维中，我们解析地预测了一个奇异的状态，其中电荷的传播速度比自旋慢，甚至可以“冻结”，这与数值计算一致。在二维空间中，驱动会减慢电荷和自旋，并导致单粒子和成对跳跃过程之间的复杂干涉。
Spin-charge separation (SCS) is a striking manifestation of strong correlations in low-dimensional quantum systems, whereby a fermion splits into separate spin and charge excitations that travel at different speeds. Here, we demonstrate that periodic driving enables control over SCS in a Hubbard system near half filling. In one dimension, we predict analytically an exotic regime where charge travels slower than spin and can even become "frozen," in agreement with numerical calculations. In two dimensions, the driving slows both charge and spin and leads to complex interferences between single-particle and pair-hopping processes.