Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, aleja Mickiewicza 30, 30-059 Kraków, Poland.
J Phys Condens Matter. 2010 Jun 2;22(21):215801. doi: 10.1088/0953-8984/22/21/215801. Epub 2010 May 5.
We study stationary electron flow through a three-terminal quantum ring and describe effects due to deflection of electron trajectories by classical magnetic forces. We demonstrate that generally at high magnetic field (B) the current is guided by magnetic forces to follow a classical path, which for B > 0 leads via the left arm of the ring to the left output terminal. The transport to the left output terminal is blocked for narrow windows of magnetic field for which the interference within the ring leads to formation of wavefunctions that are only weakly coupled to the output channel wavefunctions. These interference conditions are accompanied by injection of the current to the right arm of the ring and by appearance of sharp peaks of the transfer probability to the right output terminal. We find that these peaks at high magnetic field are attenuated by thermal widening of the transport window. We also demonstrate that the interference conditions that lead to their appearance vanish when elastic scattering within the ring is present. The clear effect of magnetic forces on the transfer probabilities disappears along with Aharonov-Bohm oscillations in a chaotic transport regime that is found for rings whose width is larger than the width of the channels.
我们研究了通过三端量子环的静止电子流，并描述了由于经典磁力使电子轨迹偏转而产生的影响。我们证明，通常在强磁场（B）下，电流受磁力引导，沿经典路径流动，对于 B > 0，该路径通过环的左臂流向左侧输出端。对于磁场的狭窄窗口，由于环内的干涉导致形成与输出通道波函数弱耦合的波函数，因此会阻止电流流向左侧输出端。这些干涉条件伴随着电流注入环的右臂以及向右侧输出端的转移概率出现尖锐峰值。我们发现，这些在强磁场下的峰值会因传输窗口的热展宽而衰减。我们还证明，当环内的弹性散射存在时，导致这些峰值出现的干涉条件会消失。随着在宽度大于通道宽度的混沌传输模式下发现的 Aharonov-Bohm 振荡，对转移概率的明显磁场影响会消失。
