Giant Influence of Clustering and Anti-Clustering of Disordered Surface Roughness on Electronic Tunneling  

作　　者：Yu Zhang Qingyun Zhang Youqi Ke Ke Xia 张羽;张青云;柯友启;夏钶(School of Physical Science and Technology,ShanghaiTech University,Shanghai 201210,China;Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Beijing Computational Science Research Center,Beijing 100193,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]School of Physical Science and Technology,ShanghaiTech University,Shanghai 201210,China [2]Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China [3]Beijing Computational Science Research Center,Beijing 100193,China [4]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Chinese Physics Letters》2022年第8期53-58,共6页中国物理快报（英文版）

基　　金：financial support from the National Natural Science Foundation of China(Grant No.11874265);Shanghaitech Startup;supported by the National Key Research and Development Program of China(Grant Nos.2017YFA0303300 and 2018YFB0407601);the National Natural Science Foundation of China(Grant Nos.11734004 and 21421003)。

摘　　要：This work reveals the giant influence of spatial distribution of disordered surface roughness on electron tunneling,which is of immediate relevance to the magneto tunnel device and imaging technologies.We calculate the spin-dependent tunneling in Fe/vacuum/Fe junction with disordered surface roughness with the first-principles non-equilibrium dynamical cluster theory.It is found that,at high concentration of surface roughness,different spatial distributions,including the clustered,anti-clustered and completely random roughness characterized by Warren–Cowley parameters,present large deviations from each other in all spin channels.By changing from clustered to anti-clustered roughness,it is surprising that spin polarization of tunneling in parallel configuration(PC)can be drastically reversed from-0.52 to 0.93,while complete randomness almost eliminates the polarization.It is found that the anti-clustered roughness can dramatically quench the tunneling of minority spin in both PC and anti-PC by orders of magnitude,but significantly enhance the transmission of majority spin in PC(by as large as 40%)compared to the results of clustered roughness,presenting distinct influences of differently correlated surface roughness.The spatial correlation of disordered surface roughness can significantly modify the surface resonance of Fe minority spin.

关 键 词：theory ROUGHNESS TUNNELING 

分 类 号：O469[理学—凝聚态物理]