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arXiv 0804.1249cond-mat.mes-hall
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利用自旋偏置操纵和测量量子点中的量子自旋

Using spin bias to manipulate and measure quantum spin in quantum dots

Hai-Zhou Lu, Shun-Qing Shen

摘要:

利用格林函数理论研究了具有自旋相关的化学势分裂(自旋偏置)的双量子点与电极的耦合。通过施加大的自旋偏置,可以以完全电的方式操纵量子点(点1)中的量子自旋。为了非侵入性地监视点1中的量子自旋的操纵,提出了第二量子点(点2)与点1弱耦合。在两个量子点之间存在交换相互作用的情况下,量子点1中的极化自旋表现得像有效磁场,并且使附近的量子点2中的自旋弱极化。通过向点2施加非常小的自旋偏置,可以探测通过点2的自旋相关输运,从而允许非破坏性地识别点1中的自旋极化。这两个步骤形成了一个完整的计划,以操纵一个被困的自旋,同时允许这种操纵被监测的双点系统使用纯电动的方法。

英文摘要:

A double-quantum-dot coupled to electrodes with spin-dependent splitting of chemical potentials (spin bias) is investigated theoretically by means of the Green's functions formalism. By applying a large spin bias, the quantum spin in a quantum dot (the dot 1) can be manipulated in a fully electrical manner. To noninvasively monitor the manipulation of the quantum spin in the dot 1, it is proposed that the second quantum dot (the dot 2) is weakly coupled to the dot 1. In the presence of the exchange interaction between the two dots, the polarized spin in the dot 1 behaves like an effective magnetic field and weakly polarizes the spin in the nearby quantum dot 2. By applying a very small spin bias to the dot 2, the spin-dependent transport through the dot 2 can be probed, allowing the spin polarization in the dot 1 to be identified nondestructively. These two steps form a complete scheme to manipulate a trapped spin while permitting this manipulation to be monitored in the double-dot system using pure electric approaches.

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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