Heating of the Mn spin system by photoexcited holes in type-II (Zn,Mn)Se/(Be,Mn)Te quantum wells

The efficiency of the Mn‐spin system heating under pulsed laser excitation is studied in diluted magnetic semiconductor heterostructures Zn0.99 Mn0.01 Se/Be0.93 Mn0.07 Te with type‐II band alignment by means of time‐resolved photoluminescence and pump‐probe reflectivity. An essential role in the heating is played by multiple spin‐flip scatterings of a hole with localized spins of Mn2+ ions. The efficiency of the spin and energy transfer from photoexcited holes to Mn ions of the Zn0.99 Mn0.01 Se layer considerably depends on the hole lifetime in this layer. This lifetime can be limited by the hole relaxation into the Be0.93 Mn0.07 Te layers and is strongly sensitive to the excitation power and Zn0.99 Mn0.01 Se layer thickness. These dependences allow us to determine a characteristic time of about 20ps for the spin and energy transfer from photoexcited holes to the Mn spin system. Which factors do affect the efficiency of the Mn‐spin system heating in ZnMn0.01Se quantum wells defined by the spin and energy transfer from photogenerated holes? 1. Multiple spin‐flip scatterings with localized Mn spins and 2. hole lifetime. It is revealed that the lifetime depends on the quantum well thickness and laser power. A characteristic heating time is evaluated to 20 ps.