在 Fe/MgO/Fe/GaAs(001) 结中通过电子过滤实现隧穿磁电阻的强增强。

Strong enhancement of the tunneling magnetoresistance by electron filtering in an Fe/MgO/Fe/GaAs(001) junction.

机构信息

Department of Mathematics, City University, London EC1V 0HB, United Kingdom.

出版信息

Phys Rev Lett. 2010 May 28;104(21):217202. doi: 10.1103/PhysRevLett.104.217202. Epub 2010 May 27.

DOI:10.1103/PhysRevLett.104.217202

PMID:20867131

Abstract

Calculations of the tunneling magnetoresistance (TMR) of an epitaxial Fe/MgO/Fe tunneling junction attached to an n-type GaAs lead, under positive gate voltage, are presented. It is shown that for realistic GaAs carrier densities the TMR of this composite system can be more than 2 orders of magnitude higher than that of a conventional Fe/MgO/Fe junction. Furthermore, the high TMR is achieved with modest MgO thicknesses and is very robust to disorder at the Fe/GaAs interface and within the GaAs layer itself. The significant practical advantage of this system is that huge TMRs should be attainable for junctions with modest resistances. For a GaAs carrier density of 10(19) cm(-3) the system is calculated to have a TMR in excess of 10,000% but its resistance is equivalent to that of a conventional Fe/MgO/Fe junction with only 6-7 at. planes of MgO.

摘要

呈现了附着在 n 型 GaAs 引线的外延 Fe/MgO/Fe 隧道结在正栅极电压下的隧道磁电阻（TMR）的计算结果。结果表明，对于实际的 GaAs 载流子密度，这种复合系统的 TMR 可以比传统的 Fe/MgO/Fe 结高出两个数量级以上。此外，高 TMR 是通过适度的 MgO 厚度实现的，并且对 Fe/GaAs 界面和 GaAs 层本身的无序非常稳健。该系统的显著实际优势在于，对于具有适度电阻的结，应该可以实现巨大的 TMR。对于 GaAs 载流子密度为 10(19) cm(-3) 的系统，计算出的 TMR 超过 10000%，但其电阻与仅具有 6-7 个 MgO 原子层的传统 Fe/MgO/Fe 结相同。