论文标题
可调山谷过滤$α$ - $ \ MATHCAL {t} _3 $ lattices
Tunable valley filtering in dynamically strained $α$-$\mathcal{T}_3$ lattices
论文作者
论文摘要
$α$ - $ \ MATHCAL {T} _3 $ lattices中的机械变形诱导不同山谷的相反方向性的本地伪磁场。当该应变配备动态驱动器时，它会产生一个互补的山谷 - 空气对称伪电场，预计会加速电子。我们建议，通过与时间相关的非均匀应变结合这些效果，可以设计出可调谷过滤设备，从而超越静态功能。我们通过实现以四末端的霍尔酒吧$α$ - $α$ - $ \ MATHCAL {t} _3 $设置为中心的振荡高斯凸起来证明这一点，并在分析上计算诱导的伪电信领域。在递归浮部绿色功能方案中，我们确定了时间平均的传播和山谷极化，以及状态和电流密度的局部密度的空间分布。由于定期驱动，我们根据$α$检测具有高谷极化传输的新型能源机制。分析时间平均状态的局部密度和电流密度的空间曲线，我们可以将这些机制与设置中的伪电磁磁场联系起来。通过驱动频率的方式，我们可以操纵Valley-Alarley-allarley-allarled-allarled状态，这可能对将来的设备应用可能是有利的。
Mechanical deformations in $α$-$\mathcal{T}_3$ lattices induce local pseudomagnetic fields of opposite directionality for different valleys. When this strain is equipped with a dynamical drive, it generates a complementary valley-asymmetric pseudoelectric field which is expected to accelerate electrons. We propose that by combining these effects by a time-dependent nonuniform strain, tunable valley filtering devices can be engineered that extend beyond the static capabilities. We demonstrate this by implementing an oscillating Gaussian bump centered in a four-terminal Hall bar $α$-$\mathcal{T}_3$ setup and calculating the induced pseudoelectromagnetic fields analytically. Within a recursive Floquet Green-function scheme, we determine the time-averaged transmission and valley polarization, as well as the spatial distributions of the local density of states and current density. As a result of the periodic drive, we detect novel energy regimes with highly valley-polarized transmission, depending on $α$. Analyzing the spatial profiles of the time-averaged local density of states and current density we can relate these regimes to the pseudoelectromagnetic fields in the setup.By means of the driving frequency, we can manipulate the valley-polarized states, which might be advantageous for future device applications.
