论文标题
光学晶格中的张量单极和负磁化效应
Tensor monopoles and negative magnetoresistance effect in optical lattices
论文作者
论文摘要
我们建议，可以通过光学晶格中的超电原子模拟一种四维（4D）的汉密尔顿人，它们在偶数范围内具有与量子度量张量相关的张量张量。详细研究了张量单极的拓扑特性和块状对应关系。通过沿其中一个维度固定动量，可以将其简化为具有非平凡手性绝缘体相的有效三维模型。使用半经典玻尔兹曼方程，我们计算了针对磁场$ b $的纵向电阻，并发现当超平面通过参数空间中的张张量单试切割时，大约$ -b^{2} $依赖性的负相对磁磁效应。我们还提出了一个实验方案，通过在3D光学晶格中引入外部周期性参数来实现这一4D哈密顿量。此外，我们表明可以通过在光学晶格中施加外部驱动器来检测量子度量张量和浆果曲率。
We propose that a kind of four-dimensional (4D) Hamiltonians, which host tensor monopoles related to quantum metric tensor in even dimensions, can be simulated by ultracold atoms in the optical lattices. The topological properties and bulk-boundary correspondence of tensor monopoles are investigated in detail. By fixing the momentum along one of the dimensions, it can be reduced to an effective three-dimensional model manifesting with a nontrivial chiral insulator phase. Using the semiclassical Boltzmann equation, we calculate the longitudinal resistance against the magnetic field $B$ and find the negative relative magnetoresistance effect of approximately $ -B^{2} $ dependence when a hyperplane cuts through the tensor monopoles in the parameter space. We also propose an experimental scheme to realize this 4D Hamiltonian by introducing an external cyclical parameter in a 3D optical lattice. Moreover, we show that the quantum metric tensor and Berry curvature can be detected by applying an external drive in the optical lattices.
