arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1311.7622cond-mat.mes-hall
收藏

无应变量子点中Mn自旋的共振光抽运

Resonant optical pumping of a Mn spin in a strain free quantum dot

L. Besombes, H. Boukari

摘要:

我们报道了II-VI族半导体无应变量子点中单个Mn原子的自旋性质。通过在CdTe衬底上晶格匹配的薄量子阱中的宽度起伏形成无应变Mn掺杂CdTe量子点。这些量子点允许在受控的应变环境中光学探测和解决锰原子的任何自旋状态。应变诱导的磁各向异性的不存在防止了Mn自旋在零磁场下的光泵浦。因此,在激子-Mn络合物的共振光激发下获得大的光致发光。在弱磁场作用下,Mn原子的电子自旋和核自旋的耦合被恢复为有效的光泵浦。观察到的磁场下的共振光致发光强度的减少很好地描述了一个模型,包括超精细耦合和剩余的晶体场分裂的Mn原子。最后,我们发现共振光致发光的二阶关联函数在短延迟下呈现大的光子聚束,这是Mn原子的电子和核自旋耦合动力学的一个探针。

英文摘要:

We report on the spin properties of individual Mn atoms in II-VI semiconductor strain free quantum dots. Strain free Mn-doped CdTe quantum dots are formed by width fluctuations in thin quantum wells lattice matched on a CdTe substrate. These quantum dots permit to optically probe and address any spin state of a Mn atom in a controlled strain environment. The absence of strain induced magnetic anisotropy prevents an optical pumping of the Mn spin at zero magnetic field. Thus, a large photoluminescence is obtained under resonant optical excitation of the exciton-Mn complex. An efficient optical pumping of the coupled electronic and nuclear spins of the Mn is restored under a weak magnetic field. The observed reduction of the resonant photoluminescence intensity under magnetic field is well described by a model including the hyperfine coupling and a residual crystal field splitting of the Mn atom. Finally, we show that the second order correlation function of the resonant photoluminescence presents a large photon bunching at short delay which is a probe of the dynamics of coupled electronic and nuclear spins of the Mn atom.

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。

↑