Electronic Pumping of Quasiequilibrium Bose-Einstein-Condensed Magnons
Electronic Pumping of Quasiequilibrium Bose-Einstein-Condensed Magnons
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DOI：
10.1103/physrevlett.108.246601
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发表时间：
2012-06-11
影响因子：
8.6
通讯作者：
Tserkovnyak, Yaroslav
中科院分区：
文献类型：
--
作者：
Bender, Scott A.;Duine, Rembert A.;Tserkovnyak, Yaroslav
本文从理论上研究了半导体与绝缘体直接接触时，准平衡玻色-爱因斯坦凝聚磁振子系统之间的自旋转移。虽然电荷转移被禁止跨越界面，自旋输运产生的绝缘体和导体自旋之间的交换耦合。在正常的绝缘体相中，自旋输运仅由热梯度和自旋扩散梯度的存在决定;同时，玻色-爱因斯坦凝聚（BEC）的存在引起了与温度无关的凝聚自旋流。取决于系统的热力学偏置，自旋可以沿任一方向穿过界面，从而产生磁振子动力学相变的可能性。我们讨论了实验的可行性，观察BEC稳定状态（由自旋Seebeck效应），这是比较熟悉的自旋转移引起的经典不稳定性。
We theoretically investigate spin transfer between a system of quasiequilibrated Bose-Einstein-condensed magnons in an insulator in direct contact with a conductor. While charge transfer is prohibited across the interface, spin transport arises from the exchange coupling between insulator and conductor spins. In a normal insulator phase, spin transport is governed solely by the presence of thermal and spin-diffusive gradients; the presence of Bose-Einstein condensation (BEC), meanwhile, gives rise to a temperature-independent condensate spin current. Depending on the thermodynamic bias of the system, spin may flow in either direction across the interface, engendering the possibility of a dynamical phase transition of magnons. We discuss the experimental feasibility of observing a BEC steady state (fomented by a spin Seebeck effect), which is contrasted to the more familiar spin-transfer-induced classical instabilities.