论文标题
浆果曲率热点的非绝热大厅效应
Non-adiabatic Hall effect at Berry curvature hot spot
论文作者
论文摘要
浆果曲率的热点通常在Bloch带反交叉处发现，在浆果阶段，大厅效应最为明显。在那里的较小间隙，在中等电场中，可以超过霍尔电流的现有配方的绝热极限。在这里，我们提出了一种非绝热大厅效应的理论，通过电场对跨间隙电子孔激发进行非扰动。我们发现场诱导的电子孔相干性和内在的霍尔速度之间的一般联系。在连贯的演化中，电子孔连贯性可以表现为较大的交流大厅速度。当考虑到环境噪声时，其与电场的联合作用有利于一种电子孔相干性的形式，该形式仅是波形和场的功能，从而导致直流非线性霍尔效应。霍尔电流在现场中具有所有奇数术语，并且仍然保留浆果曲率的内在作用。定量演示使用了Gapped Dirac锥的示例，我们的理论可用于描述带有Gapped Edge的绝缘器中的散装伪源性霍尔电流，例如石墨烯和2d Mnbi $ _ {2} $ _ {2} $ te $ _ {4} $
Hot spot of Berry curvature is usually found at Bloch band anti-crossings, where the Hall effect due to the Berry phase can be most pronounced. With small gaps there, the adiabatic limit for the existing formulations of Hall current can be exceeded in a moderate electric field. Here we present a theory of non-adiabatic Hall effect, capturing non-perturbatively the across gap electron-hole excitations by the electric field. We find a general connection between the field induced electron-hole coherence and intrinsic Hall velocity. In coherent evolution, the electron-hole coherence can manifest as a sizeable ac Hall velocity. When environmental noise is taken into account, its joint action with the electric field favors a form of electron-hole coherence that is function of wavevector and field only, leading to a dc nonlinear Hall effect. The Hall current has all odd order terms in field, and still retains the intrinsic role of the Berry curvature. The quantitative demonstration uses the example of gapped Dirac cones, and our theory can be used to describe the bulk pseudospin Hall current in insulators with gapped edge such as graphene and 2D MnBi$_{2}$Te$_{4}$
