The ultimate limit of control of light at the nanoscale is the atomic scale. By stacking multiple layers of graphene on hexagonal boron nitride (h-BN), heterostructures with unique nanophotonic properties can be constructed, where the distance between plasmonic materials can be controlled with atom-scale precision. Here we show how an atomically thick tunable quantum tunnelling device can be used as a building block for quantum plasmonics. The device consists of two layers of graphene separated by 1 nm (three monolayers) of h-BN, and a bias voltage between the layers generates an electron gas coupled to a hole gas. We show that, even though its total charge is zero, this system is capable of supporting propagating graphene plasmons.

中文翻译：

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在电荷中性量子隧穿晶体管中传播等离子体。

在纳米级控制光的最终极限是原子级。通过在六边形氮化硼（h-BN）上堆叠多层石墨烯，可以构建具有独特的纳米光子特性的异质结构，从而可以以原子级精度控制等离激元材料之间的距离。在这里，我们展示了如何将原子厚的可调谐量子隧穿设备用作量子等离子体激元的基础。该器件由两层石墨烯组成，两层石墨烯之间被1 nm的h-BN隔开（三个单层），两层之间的偏置电压产生耦合到空穴气体的电子气。我们表明，即使其总电荷为零，该系统也能够支持正在传播的石墨烯等离子体激元。