Magnetic polarons in a single diluted magnetic semiconductor quantum dot

Abstract

Quasi-zero-dimensional magnetic polarons in single Cd 0.93 Mn 0.07 Te/Cd 0.6 Mg 0.4 Te quantum dots have been studied by photoluminescence spectroscopy. By comparing the experimental data with model calculations, the energy, the internal magnetic field, and the volume of the magnetic polarons are obtained. Moreover, the magnetic environment of the recombining electron hole pair causes a distinct broadening of the emission line (ϳ4 meV) of one diluted magnetic single quantum dot. The alignment of the Mn-spins in high magnetic fields results in a linewidth narrowing of almost one order of magnitude and the linewidth becomes comparable to that of a nonmagnetic Cd 0.93 Mg 0.07 Te/Cd 0.6 Mg 0.4 Te reference sample. RAPID COMMUNICATIONS R7768PRB 62 A. A. MAKSIMOV et al. RAPID COMMUNICATIONS R7770PRB 62 A. A. MAKSIMOV et al.

Luminescence of Cd0.7Mn0.3Te crystals in magnetic field: Linewidth, Landau quantization, and carrier effective mass

“…Data reported in literature on the luminescence line FWHM dependence on magnetic field are controversial: a FWHM narrowing [19,20] as well as the FWHM increase [15,21] are calculated and observed. Our experimental results indicate that the FWHM value shows a tendency to decrease in magnetic field (Fig.…”

“…Data on the excitonic linewidth dependence on magnetic field are very scarce [15,19,20]. We took an attempt to evaluate more precisely the compositiondisorder-induced part in FWHM value in magnetic field by introducing the dE g /dx = f (B) value [5].…”

Magnetic polaron formation and exciton spin relaxation in single Cd1−xMnxTe quantum dots

“…In compound II -VI QDs the Mn doping is performed routinely enabling studies of very dilute systems including QDs with single Mn ions 4 and of highly doped ones with molar contents up to 7%. 5 Magnetic properties are comfortably monitored through optical experiments, since exchange interaction between the localized magnetic ions and the band carriers leads to pronounced magnetooptical effects. 6 In particular, energy minimization of a complex consisting of a photocreated electron-hole pair (an exciton) interacting with Mn ions, results in a spontaneous formation of a local ferromagnetic order -a magnetic polaron (MP).…”

Multiband Electronic Structure of Magnetic Quantum Dots: Numerical Studies

“…The transition energy, hν, depends on QD geometry, which typically has significant uncertainties. One should also take into account the Varshni shift when analyzing the temperature variation of hν [3]. Moreover, our calculated E MP values cannot be directly compared to MP signatures seen in those QDs, where recombination time is smaller or comparable to MP formation time [30].…”

“…the early reports in Refs. [3,4]. The first time-resolved studies of this effect in self-assembled DMS QDs were presented in Refs.…”