Chang Ching-Hao, van den Brink Jeroen, Ortix Carmine
Institute for Theoretical Solid State Physics, IFW Dresden, Helmholtzstraße 20, 01069 Dresden, Germany and Department of Physics, National Tsing Hua University, Hsinchu 30043, Taiwan.
Institute for Theoretical Solid State Physics, IFW Dresden, Helmholtzstraße 20, 01069 Dresden, Germany and Department of Physics, Technical University Dresden, D-1062 Dresden, Germany.
Phys Rev Lett. 2014 Nov 28;113(22):227205. doi: 10.1103/PhysRevLett.113.227205. Epub 2014 Nov 26.
We establish theoretically that in nonmagnetic semiconducting bilayer or multilayer thin film systems rolled up into compact quasi-one-dimensional nanoarchitectures, the ballistic magnetoresistance is very anisotropic: conductances depend strongly on the direction of an externally applied magnetic field. This phenomenon originates from the curved open geometry of rolled-up nanotubes, which leads to a tunability of the number of quasi-one-dimensional magnetic subbands crossing the Fermi energy. The experimental significance of this phenomenon is illustrated by a sizable anisotropy that scales with the inverse of the winding number, and persists up to a critical temperature that can be strongly enhanced by increasing the strength of the external magnetic field or the characteristic radius of curvature, and can reach room temperature.
我们从理论上证明，在卷绕成紧凑准一维纳米结构的非磁性半导体双层或多层薄膜系统中，弹道磁阻具有很强的各向异性：电导率强烈依赖于外加磁场的方向。这种现象源于卷绕纳米管的弯曲开放几何结构，这导致了穿过费米能量的准一维磁子带数量的可调性。这种现象的实验意义通过与缠绕数的倒数成比例且持续到临界温度的可观各向异性得到说明，该临界温度可通过增加外部磁场强度或特征曲率半径而显著提高，并且可以达到室温。
