论文标题
通过定期驾驶在狄拉克费米子中诱导各向异性
Inducing anisotropies in Dirac fermions by periodic driving
论文作者
论文摘要
我们认为，在第二代拓扑绝缘子的BI $ _2 $ SE $ _3 $的三维HAMILTONIAN下，在平面内和平面外部的周期性驱动器下。正如它将通过在Floquet Hamiltonian中高达二阶的高频扩展所示，驾驶诱导了Dirac锥体中的各向异性，并为椭圆形偏光磁场的平面距离张开了绝对差距。分析表达式获得了重新归一化的速度和准差间隙。然后，将这些表达式与通过在一维晶格中离散哈密顿量进行的数字计算进行比较，并在交错的费米昂方法之后，达到了一个显着的一致性。我们认为我们的工作可能会影响拓扑绝缘体的运输特性。
We consider the three-dimensional Hamiltonian for Bi$_2$Se$_3$, a second-generation topological insulator, under the effect of a periodic drive for both in-plane and out-of-plane fields. As it will be shown by means of high-frequency expansions up to second order in the Floquet Hamiltonian, the driving induces anisotropies in the Dirac cone and opens up a quasienergy gap for in-plane elliptically polarized fields. Analytic expressions are obtained for the renormalized velocities and the quasienergy gap. These expressions are then compared to numerical calculations performed by discretizing the Hamiltonian in a one-dimensional lattice and following a staggered fermion approach, achieving a remarkable agreement. We believe our work may have an impact on the transport properties of topological insulators.
