Electron spin transfer of single quantum dots by using teraheltz and/or laser lights

使用太赫兹和/或激光进行单量子点的电子自旋转移

基本信息

批准号：
17310056
负责人：
ADACHI Satoru
金额：
$ 8.54万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17310056/
关键词：
single quantum dot electron spin nuclear spin STIRAP quantum state control InAlAs optical bistability spin coherence InAIAs テラヘルツラマン過程結合量子ドット量子演算テラヘルツ光光支援トンネリングゼーマン分裂

项目摘要

In this project, we aimed the development of the technique to transfer the spin between the Zeeman-split electron states in a single quantum dot (QD). Then, we tried the following two methods; use of teraheltz wave and two-photon process via half-localized state in a QD. As a consequence, by the latter method, we succeeded the control of the exciton spin state and the details were published in the academic journals. In the experiments, depending on the light polarizations of the co-linearly propagating delay-controlled double pulses, we observed the in-phase and out-of-phase oscillations of photoluminescence (PL) from the Zeeman-split two exciton states. In the case of the out-of-phase oscillations, the oscillation of the Zeeman splitting energy as well as the magnitude of the PLs was observed. This is because the nuclear spin polarization in a QD was formed and followed the modulation of the electron spin polarization. This result indicates that the half-localized state of QDs is available as the intermediate state in the Lambda-type transition in order to control of the electron and nuclear spins. In addition, we investigated the hyperfine interaction between electron and nuclear spins in a single QD, and the bistability and hysteretic response of the nuclear spin polarization were observed in the dependence on excitation power, polarization, and external magnetic field. By using this nuclear spin switching, we proved that the effective g factor of the QD electron could be tuned widely from negative to positive and be set to zero.

在这个项目中，我们旨在开发该技术，以在单个量子点（QD）中传递Zeeman-Split电子状态之间的自旋。然后，我们尝试了以下两种方法。在QD中通过半局部化状态使用Teraheltz波和两光子过程。结果，通过后一种方法，我们成功地控制了激子旋转状态，并在学术期刊上发表了细节。在实验中，取决于共同传播的延迟控制的双脉冲的光线极化，我们观察到了来自Zeeman-Splimencence（PL）的相相和异相振荡。在相位外振荡的情况下，观察到Zeeman分裂能量以及PL的幅度的振荡。这是因为形成了QD中的核自旋极化，并遵循电子自旋极化的调节。该结果表明，QD的半定位状态可作为Lambda型转变中的中间状态，以控制电子和核自旋。此外，我们研究了单个QD中电子和核自旋之间的超精细相互作用，并且在对激发能力，极化和外部磁场的依赖性中观察到了核自旋极化的双重性和滞后反应。通过使用这种核自旋切换，我们证明了QD电子的有效G系数可以从阴性广泛调整为正，并设置为零。