Direct determination of the zero-field splitting for a single Co2+ ion embedded in a CdTe/ZnTe quantum dot | |
Article | |
关键词: MAGNETIZATION-STEP; AXIAL ANISOTROPY; SPIN DYNAMICS; CDSE; SEMICONDUCTOR; ZN1-XCOXO; COBALT; | |
DOI : 10.1103/PhysRevB.97.045305 | |
来源: SCIE |
【 摘 要 】
When a Co2+ impurity is embedded in a semiconductor structure, crystal strain strongly influences the zero-field splitting between Co2+ states with spin projection S-z = +/- 3/2 and S-z = +/- 1/2. Experimental evidence of this effect has been given in previous studies; however, direct measurement of the strain-induced zero-field splitting has been inaccessible so far. Here this splitting is determined thanks to magneto-optical studies of an individual Co2+ ion in an epitaxial CdTe quantum dot in a ZnTe barrier. Using partially allowed optical transitions, we measure the strain-induced zero-field splitting of the Co2+ ion directly in the excitonic photoluminescence spectrum. Moreover, by observation of anticrossing of S-z = +3/2 and S-z = -1/2 Co2+ spin states in a magnetic field, we determine the axial and in-plane components of the crystal field acting on the Co2+. The proposed technique can be applied to optical determination of the zero-field splitting of other transition-metal ions in quantum dots.
【 授权许可】
Free