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arXiv 0810.4268cond-mat.mes-hall
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硅单电子晶体管中的电子自旋阻塞和单重态-三重态跃迁

Electron spin blockade and singlet-triplet transition in a silicon single electron transistor

Binhui Hu, C. H. Yang

摘要:

我们研究了一个金属氧化物半导体(MOS)结构的硅单电子晶体管(SET),通过施加一个垂直于样品表面的磁场。量子点被静电地限定在点接触通道中并且由来自带负电荷的界面陷阱的势垒限定。激发光谱的磁场依赖性主要由塞曼效应驱动。在双电子单重态-三重态(ST)跃迁中,电子-电子库仑相互作用起着重要作用。库仑阻塞峰随磁场B的演化也是塞曼分裂的结果,在9T以下没有明显的轨道效应。填充图案显示交替的自旋向上-自旋向下序列。的振幅谱允许观察的自旋封锁效应,其中的两个电子系统在低场形成单重态,和自旋极化的注入从铅减少了隧穿电导的一个因素的8。在较高的磁场下,由于ST转变,自旋阻塞效应被解除,电导完全恢复。

英文摘要:

We investigate a silicon single-electron transistor (SET) in a metal-oxide-semiconductor (MOS) structure by applying a magnetic field perpendicular to the sample surface. The quantum dot is defined electrostatically in a point contact channel and by the potential barriers from negatively charged interface traps. The magnetic field dependence of the excitation spectrum is primarily driven by the Zeeman effect. In the two-electron singlet-triplet (ST) transition, electron-electron Coulomb interaction plays a significant role. The evolution of Coulomb blockade peaks with magnetic field B is also owing to the Zeeman splitting with no obvious orbital effect up to 9 T. The filling pattern shows an alternate spin-up-spin-down sequence. The amplitude spectroscopy allows for the observation of the spin blockade effect, where the two-electron system forms a singlet state at low fields, and the spin polarized injection from the lead reduces the tunneling conductance by a factor of 8. At a higher magnetic field, due to the ST transition, the spin blockade effect is lifted and the conductance is fully recovered.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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