论文标题
由Andreev Tunneling驱动的纳米力学
Nano-mechanics driven by Andreev tunneling
论文作者
论文摘要
我们预测并分析了机械不稳定性和相应的自我维持的机械振荡，该机械振荡发生在纳米机械系统中，该系统由悬浮在两个超导导线之间的金属碳纳米管（CNT）组成，并偶联到扫描隧道显微镜（STM）尖端。我们表明，这种现象是在CNT和超导导线之间相干的AndReev隧穿的情况下实现的，并且在电压偏置的STM尖端和CNT之间进行了不一致的单电子隧穿。将CNT视为单级量子点，我们证明了机械不稳定性由约瑟夫森相位差，电子能级的相对位置以及电荷流的方向控制。从数值上发现，自我维持的振荡的出现会导致对直流电流的实质性抑制。
We predict and analyze mechanical instability and corresponding self-sustained mechanical oscillations occurring in a nanoelectromechanical system composed of a metallic carbon nanotube (CNT) suspended between two superconducting leads and coupled to a scanning tunneling microscope (STM) tip. We show that such phenomena are realized in the presence of both the coherent Andreev tunneling between the CNT and superconducting leads, and an incoherent single electron tunneling between the voltage biased STM tip and CNT. Treating the CNT as a single-level quantum dot, we demonstrate that the mechanical instability is controlled by the Josephson phase difference, relative position of the electron energy level, and the direction of the charge flow. It is found numerically that the emergence of the self-sustained oscillations leads to a substantial suppression of DC electric current.
