论文标题
石墨烯断裂连接中的机械可调量子点
A Mechanically Tunable Quantum Dot in a Graphene Break Junction
论文作者
论文摘要
深入研究石墨烯量子点（QD）作为下一代量子电子设备的平台。单层石墨烯QD中传输性能的微调，特别是在隧道屏障透明胶片的独立调制方面，仍然具有挑战性，通常使用静电门控解决。我们研究了后门控石墨烯机械断裂连接的电荷传输，并揭示了单个高质量QD的库仑封锁物理特征，当时是在石墨烯收缩中打开的纳米op时。通过机械控制新形成的石墨烯纳米摄体仪的距离，我们可以通过五个数量级实现隧道耦合到排水电极的可逆可调节性，同时保持源-QD隧道偶联的恒定。这些发现表明，隧道耦合不对称可以通过机械调整旋钮进行显着调节，并且对未来基于石墨烯的设备的开发具有重要意义，包括能量转换器和量子量热量表。
Graphene quantum dots (QDs) are intensively studied as platforms for the next generation of quantum electronic devices. Fine tuning of the transport properties in monolayer graphene QDs, in particular with respect to the independent modulation of the tunnel barrier transparencies, remains challenging and is typically addressed using electrostatic gating. We investigate charge transport in back-gated graphene mechanical break junctions and reveal Coulomb blockade physics characteristic of a single, high-quality QD when a nanogap is opened in a graphene constriction. By mechanically controlling the distance across the newly-formed graphene nanogap, we achieve reversible tunability of the tunnel coupling to the drain electrode by five orders of magnitude, while keeping the source-QD tunnel coupling constant. These findings indicate that the tunnel coupling asymmetry can be significantly modulated with a mechanical tuning knob and has important implications for the development of future graphene-based devices, including energy converters and quantum calorimeters.
