Spin-lattice relaxation of Mn ions inZnMnSe∕ZnBeSequantum wells measured under pulsed photoexcitation

Abstract

The dynamics of spin-lattice relaxation of the Mn-ions in (Zn,Mn)Se-based diluted-magnetic-semiconductor quantum wells is studied by time-resolved photoluminescence.The spin-lattice relaxation time varies by five orders of magnitude from 10 -3 down to 10 -8 s, when the Mn content increases from 0.4 up to 11%. Free carriers play an important role in this dynamics. Hot carriers with excess kinetic energy contribute to heating of the Mn system, while cooling of the Mn system occurs in the presence of cold background carriers provided by modulation doping. In a Zn 0.89 Mn 0.11 Se quantum well structure, where the spin-lattice relaxation process is considerably shorter than the characteristic lifetime of nonequilibrium phonons, also the phonon dynamics and its contribution to heating of the Mn system are investigated.PACS: 75.50. Pp, 78.55.Et, 78.20.Ls, 2

Time-resolved magnetophotoluminescence studies of magnetic polaron dynamics in type-II quantum dots

“…11 we plot T could be due to the high-peak power of the pulsed laser used to excite the TR-PL spectra. 58 In Fig. 11, if we consider T > 7 K, we have a weak dependence of MP E (T) , close to the results of Fig.…”

Electric field control of magnetization dynamics in ZnMnSe∕ZnBeSe diluted-magnetic-semiconductor heterostructures

“…The Mn spin system polarized by an external magnetic field was heated by a pulsed laser and the dynamical shift of the photoluminescence (PL) line was detected (for details see Ref. [6]). at B = 3 T due to weak heating of the Mn system by the electrical current through the structure (see Fig.…”

“…of the Mn spin system can be obtained by means of the giant Zeeman splitting of excitonic states in external magnetic fields [6]:…”

“…The magnetization dynamics of the Mn spin system can be analysed from the temporal evolution of the Zeeman shift induced by the laser pulses (could be omitted, as mentioned already a few times: in external magnetic fields) [6]. The Mn spin system is heated up during the laser pulses and is cooled down between the pulses back to lattice temperature.…”

“…SLR time as long as 530 µs have been reported for an undoped of (Zn,Mn)Se/(Zn,Be)Se QW with a Mn concentration of x = 0.015 (sample #6 in Ref. [6]). …”