Propagation effect on photoluminescence of spin-aligned high-density exciton magnetic polarons in Cd 0.8 Mn 0.2 Te

Carrier and spin dynamics of high-density exciton magnetic polarons in Cd0.8Mn0.2Te

“…The PL intensity was proportional to the 4th power of the excitation density. The red-shift of the PL peak energy and the non-linearity of the PL intensity of the HD-EMPs exhibit the same behavior as observed in previous studies [30][31][32][33].…”

“…In addition, the photon energy dependence of the DOCP was affected by the refringence, which could not be analytically excluded. The rapid change in the DOCP for high photon energies originated from the unexpected birefringence in the sample [32,33]. In contrast, the DOP was lower for the σ − excitation than for the σ + excitation.…”

“…Under circularly polarized excitation, the PL of the HD-EMPs was highly polarized, the degree of circular polarization (DOCP) was dependent on the photon energy due to the birefringence of the sample [32]. However, it was revealed that the PL was initially circularly polarized, and that the DOCP was almost constant for the entire PL band, which supports the generation of the high-spin state of the HD-EMPs [33]. Consequently, the spin-aligned state of the HD-EMPs was revealed using circularly polarized excitation light.…”

“…The possibility of EHP as the origin of the PL is eliminated since it appears only under the selective excitation of the localized excitons. In our previous study, we reported on the propagation effect on the PL of the HD-EMPs and its polarization, when the PL was collected in a forward scattering configuration [33]. The directivity of the emission from the HD-EMP band was clearly observed although the LMP band did not exhibit directivity because it resulted from spontaneous emission.…”

“…For Cd 0.8 Mn 0.2 Te, we reported on non-linearly enhanced PL for high-density EMPs (HD-EMPs) excited by a selective excitation of the localized exciton states, where the excitation photon energy was lower than the mobility edge [30][31][32][33]. The PL peak energy of the HD-EMP exhibited a redshift with the increase of the excitation density.…”