Controlling the interaction of electron and nuclear spins in a tunnel-coupled quantum dot.
Controlling the interaction of electron and nuclear spins in a tunnel-coupled quantum dot.
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DOI：
10.1103/physrevlett.106.046802
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发表时间：
2010-10
影响因子：
8.6
通讯作者：
Christoph Kloeffel;P. Dalgarno;B. Urbaszek;B. Gerardot;D. Brunner;P. Petroff;D. Loss;R. Warburton;R. Warburton
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文献类型：
--
作者：
Christoph Kloeffel;P. Dalgarno;B. Urbaszek;B. Gerardot;D. Brunner;P. Petroff;D. Loss;R. Warburton;R. Warburton
我们提出了一种操纵单个光学活性量子点的核自旋和发射极化的技术。当量子点被隧道耦合到费米海时，我们发现了一个自然循环，在这个循环中，电子自旋被共振光激发重复产生。自发辐射极化和核自旋极化表现为双稳态。对于σ(+)泵浦，在激光器的特定失谐时，发射从σ(+)切换到σ(-)。同时，原子核的自旋极化由正向负转变。除了双稳，核自旋极化可以从负到正连续变化，允许通过激光波长进行精确控制。
We present a technique for manipulating the nuclear spins and the emission polarization from a single optically active quantum dot. When the quantum dot is tunnel coupled to a Fermi sea, we have discovered a natural cycle in which an electron spin is repeatedly created with resonant optical excitation. The spontaneous emission polarization and the nuclear spin polarization exhibit a bistability. For a σ(+) pump, the emission switches from σ(+) to σ(-) at a particular detuning of the laser. Simultaneously, the nuclear spin polarization switches from positive to negative. Away from the bistability, the nuclear spin polarization can be changed continuously from negative to positive, allowing precise control via the laser wavelength.