Lee Kang Hao, Balachandran Vinitha, Tan Ryan, Guo Chu, Poletti Dario
Science, Mathematics and Technology Cluster, Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372, Singapore.
Engineering Product Development Pillar, Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372, Singapore.
Entropy (Basel). 2020 Nov 17;22(11):1311. doi: 10.3390/e22111311.
In XXZ chains with large enough interactions, spin transport can be significantly suppressed when the bias of the dissipative driving becomes large enough. This phenomenon of negative differential conductance is caused by the formation of two oppositely polarized ferromagnetic domains at the edges of the chain. Here, we show that this many-body effect, combined with a non-uniform magnetic field, can allow for a high degree of control of the spin current. In particular, by studying all of the possible shapes of local magnetic fields potentials, we find that a configuration in which the magnetic field points up for half of the chain and down for the other half, can result in giant spin-current rectification, for example, up to 108 for a system with only 8 spins. Our results show clear indications that the rectification can increase with the system size.
在具有足够大相互作用的XXZ链中，当耗散驱动的偏置足够大时，自旋输运可被显著抑制。这种负微分电导现象是由链边缘形成的两个反极化铁磁畴引起的。在此，我们表明这种多体效应与非均匀磁场相结合，能够实现对自旋电流的高度控制。特别地，通过研究局部磁场势的所有可能形状，我们发现一种磁场在链的一半向上而在另一半向下的配置，可导致巨大的自旋电流整流，例如，对于一个仅有8个自旋的系统，整流率可达108。我们的结果清楚地表明，整流率可随系统尺寸增加。
