我们重新回顾了反常霍尔效应(AHE)的模型计算,并表明,在具有点状势杂质的各向同性Rashba耦合二维电子气(2DEG)中,半经典Boltzmann方程(SBE)的完全解可能不同于广泛使用的$1/τ^{||}$和$1/τ^{\perp}$解[Phys. Rev. B 68,165311(2003)]。我们对AHE的方法类似于各向异性磁阻的基于SBE的分析,导致分布函数的积分方程[Phys.Rev.B79,045427(2009)],但在本例中,我们将描述简化为带折射率相关的输运弛豫时间。当两个Rashba带都被部分占据时,这些通过求解线性方程组来确定。详细的计算表明,对于本征散射和混合斜散射,当费米能级较大时,$1/τ^{||}$和$1/τ^{\perp}$与SBE完全解的差别是显著的。对于坐标偏移效应,在带间弹性散射过程中获得的侧跳速度被证明是更重要的较大的Rashba耦合,甚至可能超过带内的外部Rashba带。在所考虑的情况下,坐标位移对AHE的贡献显着不同于之前分析的光滑无序势的限制。
英文摘要:
We revisit model calculations of the anomalous Hall effect (AHE) and show that, in isotropic Rashba-coupled two-dimensional electron gas (2DEG) with pointlike potential impurities, the full solution of the semiclassical Boltzmann equation (SBE) may differ from the widely-used $1/τ^{||}$ & $1/τ^{\perp}$ solution [Phys. Rev. B 68, 165311 (2003)]. Our approach to AHE is analogous to the SBE-based analysis of the anisotropic magnetoresistance leading to an integral equation for the distribution function [Phys. Rev. B 79, 045427 (2009)] but in the present case, we reduce the description to band-index-dependent transport relaxation times. When both Rashba bands are partially occupied, these are determined by solving a system of linear equations. Detailed calculations show that, for intrinsic and hybrid skew scatterings the difference between $1/τ^{||}$ & $1/τ^{\perp}$ and the full solution of SBE is notable for large Fermi energies. For coordinate-shift effects, the side-jump velocity acquired in the inter-band elastic scattering process is shown to be more important for larger Rashba coupling and may even exceed the intra-band one for the outer Rashba band. The coordinate-shift contribution to AHE in the considered case notably differs from that in the limit of smooth disorder potential analyzed before.
Analytic Formulas for the Anomalous Hall Effect in Itinerant Magnets
French American Center for Theoretical Science, CNRS(法美理论科学中心,法国国家科学研究中心);Kavli Institute for Theoretical Physics, University of California, Santa Barbara(卡弗里理论物理研究所,加州大学圣塔芭芭拉分校);École Normale Supérieure de Lyon, CNRS, Laboratoire de physique(里昂高等师范学校,法国国家科学研究中心,物理实验室)
Normal and intrinsic anomalous Hall effect in Nb1-yFe2+y
本文研究了Nb_(1-y)Fe_(2 +y)系列样品的霍尔效应。正常和异常的贡献,观察到正正常霍尔效应在高温下占主导地位。一致的异常贡献的分析是唯一可能的富铁Nb 0.985 Fe 2.015具有铁磁基态。在这里,一个积极的正常霍尔系数被发现在所有的温度与适度的最大值在自旋密度波过渡。反常的霍尔效应与本征(贝里相)贡献一致,本征贡献在有序温度TC以下是恒定的,在TC以上连续消失。对于化学计量的NbFe 2和富Nb的Nb 1.01 Fe 1.99-都具有自旋密度波基态-霍尔电阻率的额外贡献阻碍了完整的分析,并表明需要更复杂的模型的异常霍尔效应在巡回反铁磁体。
Observation of anomalous thermal Hall effect in altermagnets
Fudan University(复旦大学);Shanghai Research Center for Quantum Sciences(上海量子科学研究与创新中心);ShanghaiTech University(上海科技大学);Hefei National Laboratory(合肥国家实验室);Collaborative Innovation Center of Advanced Microstructures(先进微结构协同创新中心)
Ab initio prediction of anomalous Hall effect in antiferromagnetic CaCrO$_3$
Institute of Scientific and Industrial Research, Osaka University(大阪大学科学工业研究所);Department of Precision Engineering, Graduate School of Engineering, Osaka University(大阪大学大学院工学研究科精密工程专攻)
Anomalous Hall Resistance in Bilayer Quantum Hall Systems
本文在非对易几何的基础上提出了双层量子霍尔系统中霍尔电流的微观理论。通过对海森堡运动方程和电荷连续性方程的分析,论证了在层间相位相干自发发展的系统中,相流的出现。相电流的安排本身,以尽量减少系统的总能量,诱导某些异常行为的霍尔电流在逆流的几何形状,也在拖动实验。它们解释了最近Kellogg等人[M. Kellogg,I. B. Spielman,J.P. Eisenstein,L.N. Pfeiffer和K.W. West,Phys. Rev. Lett. \textbf{88}(2002)126804; M. Kellogg,J.P. Eisenstein,L.N. Pfeiffer和K.W. West,Phys. Rev. Lett. \textbf{93}(2004)036801]和Tutuc等人[E. Tutuc,M. Shayegan和D.A. Huse,Phys. Rev. Lett. \textbf{93}(2004)036802]在$ν=1$。