Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Phys Rev Lett. 2010 Apr 23;104(16):167204. doi: 10.1103/PhysRevLett.104.167204. Epub 2010 Apr 22.
The valence-band structure and the Fermi level (E(F)) position of ferromagnetic-semiconductor GaMnAs are quantitatively investigated by electrically detecting the resonant tunneling levels of a GaMnAs quantum well (QW) in double-barrier heterostructures. The resonant level from the heavy-hole first state is clearly observed in the metallic GaMnAs QW, indicating that holes have a high coherency and that E(F) exists in the band gap. Clear enhancement of tunnel magnetoresistance induced by resonant tunneling is demonstrated in these double-barrier heterostructures.
通过电探测双势垒异质结构中 GaMnAs 量子阱的共振隧道能级，定量研究了铁磁半导体 GaMnAs 的价带结构和费米能级（E(F)）位置。在金属 GaMnAs 量子阱中，明显观察到来自重空穴第一态的共振能级，这表明空穴具有高相干性，并且费米能级存在于能带隙中。在这些双势垒异质结构中，共振隧道诱导的隧道磁电阻得到了明显增强。
