Time-resolved luminescence of high-density magnetic polarons in CdMnTe

Excitation intensity dependence of photoluminescence signals is observed in Cd0.9Mn0.1Te at View the MathML source with varying exciton density from 1014 to View the MathML source. For intermediate density regime View the MathML source, the transient spectral shift reflecting the magnetic polaron formation is found to decrease with an increase in density. For high-density regime View the MathML source, the polaron shift disappears, and the density-dependent red shift caused by the band-gap renormalization is observed. The experimental findings demonstrate that the magnetic polaron is unstable at high-density condition.