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arXiv 1607.00403cond-mat.mes-hall
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磁性隧道结中库仑交换耦合的微观理论

Microscopic theory of the Coulomb based exchange coupling in magnetic tunnel junctions

O. G. Udalov, I. S. Beloborodov

摘要:

基于磁性隧道结(MTJ)中传导电子间的多体库仑相互作用,研究了层间交换耦合(IEC)。这种机制补充了基于虚拟电子跳跃(或自旋电流)的已知IEC。我们发现这两种机制对系统参数有不同的行为。基于库仑的IEC可以超过基于跳跃的交换耦合。我们表明,库仑交换耦合,在对比跳跃耦合,强烈依赖于绝缘层的介电常数。IEC对MTJ中绝缘层的介电性质的依赖性类似于其中电和磁自由度耦合的磁电(ME)效应。我们计算了具有铁电(FE)层的MTJ的IEC作为温度和电场的函数,并且表明IEC在FE相变附近急剧减小,并且随着外部电场而强烈变化。

英文摘要:

We study interlayer exchange coupling (IEC) based on the many-body Coulomb interaction between conduction electrons in magnetic tunnel junction (MTJ). This mechanism complements the known IEC based on virtual electron hopping (or spin currents). We find that these two mechanisms have different behavior on system parameters. The Coulomb based IEC may exceed the hopping based exchange coupling. We show that the Coulomb based exchange coupling, in contrast to the hopping based coupling, depends strongly on the dielectric constant of the insulating layer. The dependence of the IEC on the dielectric properties of the insulating layer in MTJ is similar to magneto-electric (ME) effect where electric and magnetic degrees of freedom are coupled. We calculate the IEC as a function of temperature and electric field for MTJ with ferroelectric (FE) layer and show that IEC has a sharp decrease in the vicinity of the FE phase transition and varies strongly with external electric field.

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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