Magnetic polaron formation and exciton spin relaxation in single CdMnTe quantum dots

Abstract

We study the formation dynamics of a spontaneous ferromagnetic order in single self-assembled CdMnTe quantum dots. By measuring time-resolved photoluminescence, we determine the formation times for QDs with Mn ion contents x varying from 0.01 to 0.2. At low x these times are orders of magnitude longer than exciton spin relaxation times evaluated from the decay of photoluminescence circular polarization. This allows us to conclude that the direction of the spontaneous magnetization is determined by a momentary Mn spin fluctuation rather than resulting from an optical orientation. At higher x, the formation times are of the same order of magnitude as found in previous studies on higher dimensional systems. We also find that the exciton spin relaxation accelerates with increasing Mn concentration.

arXiv commentsent to Physical Review B

References in corpus (9)

• Ferromagnetism mediated by few electrons in a semimagnetic quantum dot
• Exciton spin relaxation in single semiconductor quantum dots
• Optically Induced Magnetization of CdMnTe Self-Assembled Quantum Dots
• Tailoring Magnetism in Quantum Dots
• Optically induced energy and spin transfer in non-resonantly coupled pairs of self-assembled CdTe/ZnTe quantum dots
• Voltage-tunable ferromagnetism in semimagnetic quantum dots with few particles: magnetic polarons and electrical capacitance
• Brightening of dark excitons in a single quantum dot containing a single magnetic ion
• Robust Magnetic Polarons in Type-II (Zn,Mn)Te Quantum Dots
• Exciton Spin Relaxation Time in Quantum Dots Measured by Continuous-Wave Photoluminescence Spectroscopy

Cited by in corpus (19)

• Designing quantum dots for solotronics
• Direct Measurements of Magnetic Polarons in Cd${}_{1-x}$Mn${}_x$Se Nanocrystals from Resonant Photoluminescence
• Optical control of the spin state of two Mn atoms in a quantum dot
• Stark Spectroscopy and Radiative Lifetimes in Single Self-Assembled CdTe Quantum Dots
• Spin dynamics of a confined electron interacting with magnetic or nuclear spins: A semiclassical approach
• Time-resolved magnetophotoluminescence studies of magnetic polaron dynamics in type-II quantum dots
• Origin of luminescence quenching in structures containing CdSe/ZnSe quantum dots with a few Mn${}^{2+}$ ions
• Influence of exciton spin relaxation on the photoluminescence spectra of semimagnetic quantum dots
• Spin ordering in magnetic quantum dots: From core-halo to Wigner molecules
• Reentrant Formation of Magnetic Polarons in Quantum Dots
• Effect of electron-hole separation on optical properties of individual Cd(Se,Te) Quantum Dots
• Spin-orbit coupled particle in a spin bath
• Magnetic ordering in quantum dots: Open vs. closed shells
• Multiband Electronic Structure of Magnetic Quantum Dots: Numerical Studies
• Mechanisms of optical orientation of an individual Mn${}^{2+}$ ion spin in a II-VI quantum dot
• Dynamical Magnetic and Nuclear Polarization in Complex Spin Systems: Semi-magnetic II-VI Quantum Dots
• Readout of a dopant spin in the anisotropic quantum dot with a single magnetic ion
• Magnetic-field-induced abrupt spin state transition in a quantum dot containing magnetic ions
• Optical signatures of spin dependent coupling in semimagnetic quantum dot molecules