论文标题
跨石墨烯PN连接的电气可切换隧道：$ν= 0 $状态的倾斜抗铁磁阶段的证据
Electrically switchable tunneling across a graphene pn junction: evidence for canted antiferromagnetic phase in $ν=0$ state
论文作者
论文摘要
垂直磁场中电荷中立的石墨烯片的基态仍然存在神秘性，各种实验支持倾斜的抗抗铁磁，键有序，甚至是电荷密度波阶段。阐明该状态性质的有希望的途径是将其夹在不同填充因子的区域之间，并在界面的边缘模式上研究旋转依赖性隧道。在这里，我们在$ν= 0 $区域的隧道运输中报告了固定的单层氮化物（$ hbn $）封装的单层石墨烯设备，其中$ν= 0 $ scripalized spin-parlarized $ν= \ pm1 $ pm1 $量子厅列。我们观察到$ν= \ pm1 $边缘之间的有限隧道（$ t \ sim 0.3-0.6 $）的磁场（$ b> 3t $）和低隧道偏置电压（$ <30-60μV$）（$ <30-60μV$），这是令人惊讶的，因为这是令人惊讶的，因为Edge States的电子名义上的电子名义上的闪闪函与大弹性相反。 Hartree-fock计算阐明了这些现象是由$ν= 0 $区域在零偏置处的$ν= 0 $区域的形成驱动的（对于足够宽的连接），导致边缘非正交旋转。值得注意的是，可以通过增加偏差来控制这种隧道。偏置电压在交界处导致电荷堆积，导致CAF秩序的崩溃并抑制隧道。
The ground state of a graphene sheet at charge neutrality in a perpendicular magnetic field remains enigmatic, with various experiments supporting canted antiferromagnetic, bond ordered, and even charge density wave phases. A promising avenue to elucidating the nature of this state is to sandwich it between regions of different filling factors, and study spin-dependent tunneling across the edge modes at the interfaces. Here we report on tunnel transport through a $ν=0$ region in a graphite-gated, hexagonal boron nitride ($hBN$) encapsulated monolayer graphene device, with the $ν=0$ strip sandwiched by spin-polarized $ν=\pm1$ quantum Hall states. We observe finite tunneling ($t \sim 0.3-0.6$) between the $ν=\pm1$ edges at not too small magnetic fields ($B>3T$) and low tunnel bias voltage ($<30-60μV$), which is surprising because electrons at the edge states nominally have opposite spins. Hartree-Fock calculations elucidate these phenomena as being driven by the formation of a CAF order parameter in the $ν=0$ region at zero bias (for wide enough junctions) leading to non-orthogonal spins at the edges. Remarkably, this tunneling can be controllably switched off by increasing bias; bias voltage leads to a pileup of charge at the junction, leading to a collapse of the CAF order and a suppression of the tunneling.
