Optical signatures of spin dependent coupling in semimagnetic quantum dot molecules

Abstract

We present photoluminescence studies of CdTe and CdMnTe quantum dots grown in two adjacent layers. We show that when the dots are 8 nm apart, their magnetooptical properties - Zeeman shifts and transition linewidths - are analogous to those of individual CdTe or CdMnTe dots. When the dots are grown closer, at a distance of 4 nm, it becomes possible to tune the electron states to resonance and obtain a formation of a molecular state hybridized over the two dots. As a result of the resonant enhancement of the electron-Mn ion exchange interaction, spectroscopic signatures specific to spin-dependent inter-dot coupling appear. Namely, an anomalous increase of the Zeeman shift and a resonant increase in the transition linewidth are observed. A simple model calculation allows us to quantitatively reproduce the experimental results.

submitted to Physical Review B

References in corpus (9)

• Driven coherent oscillations of a single electron spin in a quantum dot
• Direct Observation of Controlled Coupling in an Individual Quantum Dot Molecule
• Ultrafast optical control of entanglement between two quantum dot spins
• Excitation mechanisms of individual CdTe/ZnTe quantum dots studied by photon correlation spectroscopy
• Optically induced energy and spin transfer in non-resonantly coupled pairs of self-assembled CdTe/ZnTe quantum dots
• Photoluminescence Spectroscopy of the Molecular Biexciton in Vertically Stacked Quantum Dot Pairs
• Magnetic polaron formation and exciton spin relaxation in single CdMnTe quantum dots
• Optical study of electron-electron exchange interaction in CdTe/ZnTe quantum dots
• Influence of exciton spin relaxation on the photoluminescence spectra of semimagnetic quantum dots