介观金属环中量子干涉晶体管对电子相干性的影响

研究了介观金属环1个通道上的量子干涉晶体管的栅极电压及其在通道上的位置对电子相干性的影响。理论结果表明,一般情况下改变栅极长度L6(下通道长度L2)会使透射率以π(2π)周期性变化。同时发现栅极在通道上的位置对透射率的周期性不产生影响,仅改变透射率的大小。但当kL6=nπ时,透射率为kL2的函数,周期为π;当kL6=(2n+1)2π时,量子干涉晶体管的位置不影响电子透射率的相干性;当上、下通道长度相等,且kL2=kL=nπ时,透射率恒为1,与栅极长度及其在通道上的位置无关。

Electronic coherence influenced by quantum-interference transistor in metallic ring of mesoscopic system

This paper discasses the electronic coherence affected by the voltage and the position of quantum-interference transistor's gate on one arm of metallic ring of mesoscopic system.The theoretical results indicate that,generally changing the length L_6 of the gate(the length L_2 of the lower arm) can make transmissivity have the periodic variation whose period is π(2π),and simultaneously it is found that the position of quantum-interference transistor's gate on the arm doesn't influence the periodicity of the transmissivity,but only changes the size of the transmissivity,and the period of transmissivity as function of kL_2 will be π when kL_6 is equal to nπ;quantum-interference transistor will not influence the coherence of electronic transmissivity when kL_6 is equal to (2n+1)]2π;the transmissivity will be permanently equal to 1,and irrelevant with the length of the gate and the position of quantum-interference transistor's gate on the arm when kL_2 and kL are both equal to nπ.