We study the ballistic transport of a two-dimensional (2D) electron gas with anisotropic semi-Dirac (SD) band structure modulated by magnetic and electrical barriers. The magnetic barriers are induced by an inhomogeneous magnetic field, which can form a parallel (P) or antiparallel (AP) magnetic configuration. Using the transfer matrix approach, we calculate the transport-direction-dependent transmission and the conductance in P and AP configurations, respectively. For transport along the direction with linear dispersion, the magnetoresistance (TMR) oscillates with the Fermi energy and even varies from positive to negative due to the Klein tunneling. Whereas for transport along the direction with parabolic dispersion, the TMR is always positive, and there is a huge TMR within a range of energies due to the severe mismatch of the wavevector in the case of AP configuration. For the transport along an arbitrary direction, interestingly, the oscillation patterns of TMR are similar to those along the linear direction, but the amplitude of TMR is observably enhanced by two orders in magnitude. This unusual feature of TMR is originated from the anisotropic band structure of the system which suppresses the Klein tunneling. Our results are useful in designing magnetic memories based on 2D SD systems.

我们研究具有各向异性的半狄拉克（SD）带结构的二维（2D）电子气的弹道输运，该结构由磁和电势垒调制。磁障由不均匀的磁场感应，该磁场可以形成平行（P）或反平行（AP）磁配置。使用传输矩阵方法，我们分别计算了与传输方向相关的传输和P和AP配置中的电导。对于沿线性色散方向的传输，磁致电阻（TMR）随费米能量振荡，甚至由于克莱因隧穿而从正变负。对于沿抛物线色散方向的运输，TMR始终为正，在AP配置的情况下，由于波矢的严重失配，在一定的能量范围内存在巨大的TMR。对于沿任意方向的传输，有趣的是，TMR的振荡模式与沿线性方向的振荡模式相似，但可观察到的是，TMR的幅度增加了两个数量级。TMR的这一不寻常特征源自抑制Klein隧穿的系统各向异性带结构。我们的结果对于设计基于2D SD系统的磁存储器很有用。TMR的这一不寻常特征源自抑制Klein隧穿的系统各向异性带结构。我们的结果对于设计基于2D SD系统的磁存储器很有用。TMR的这一不寻常特征源自抑制Klein隧穿的系统各向异性带结构。我们的结果对于设计基于2D SD系统的磁存储器很有用。