Khrapai V S, Ludwig S, Kotthaus J P, Tranitz H P, Wegscheider W
Center for NanoScience and Department für Physik, Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, D-80539 München, Germany.
Phys Rev Lett. 2007 Aug 31;99(9):096803. doi: 10.1103/PhysRevLett.99.096803.
We study the interaction between two adjacent but electrically isolated quantum point contacts (QPCs). At high enough source-drain bias on one QPC, the drive QPC, we detect a finite electric current in the second, unbiased, detector QPC. The current generated at the detector QPC always flows in the opposite direction than the current of the drive QPC. The generated current is maximal, if the detector QPC is tuned to a transition region between its quantized conductance plateaus and the drive QPC is almost pinched-off. We interpret this counterflow phenomenon in terms of an asymmetric phonon-induced excitation of electrons in the leads of the detector QPC.
我们研究了两个相邻但电绝缘的量子点接触（QPC）之间的相互作用。在一个QPC（驱动QPC）上施加足够高的源漏偏压时，我们在第二个未加偏压的探测器QPC中检测到有限的电流。探测器QPC处产生的电流总是与驱动QPC的电流方向相反。如果将探测器QPC调谐到其量子化电导平台之间的过渡区域，且驱动QPC几乎夹断，则产生的电流最大。我们根据探测器QPC引线中电子的非对称声子诱导激发来解释这种逆流现象。
