Spin-PolarizedMn2+Emission from Mn-Doped Colloidal Nanocrystals

Abstract

We report magnetophotoluminescence studies of strongly quantum-confined 0D diluted magnetic semiconductors (DMS), realized in Mn(2+)-doped ZnSe/CdSe core-shell colloidal nanocrystals. In marked contrast to their 3D (bulk), 2D (quantum well), 1D (quantum wire), and 0D (self-assembled quantum dot) DMS counterparts, the ubiquitous yellow emission band from internal d-d ((4)T(1)→(6)A(1)) transitions of the Mn(2+) ions in these nanocrystals is not suppressed in applied magnetic fields and does become circularly polarized. This polarization tracks the Mn(2+) magnetization, and is accompanied by a sizable energy splitting between right- and left-circular emission components that scales with the exciton-Mn sp-d coupling strength (which, in turn, is tunable with nanocrystal size). These data highlight the influence of strong quantum confinement on both the excitation and the emission mechanisms of magnetic ions in DMS nanomaterials.

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

“…[1][2][3][4] Compared to their bulk counterparts, [5][6][7][8][9] magnetically doped semiconductor QDs could provide control of the magnetic ordering, [10][11][12][13][14][15][16] with the onset of magnetization at substantially higher temperatures. [17][18][19][20][21] Experiments typically focus on Mn-doped II-VI and III-V QDs, in which it is possible to include both single [22][23][24][25] and several magnetic impurities, [17][18][19][20][21][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] having similarities with nuclear spins. 41,42 In the first case (single magnetic ion), such systems could be considered as potential quantum bits, quantum memories, or probes to detect an unconventional orbital ordering.…”

Recent Advances in Magnetic Ion-Doped Semiconductor Quantum Dots

“…However, the Mn emission which is basically a spin and orbital forbidden emission does not demonstrate any polarization 58 as expected and is shown in Figure 6 a and b. Surprisingly, it was observed that in three dimensionally confined QDs, Mn emission was observed to be polarized in the presence of magnetic field 59 as shown in Figure 6 c and d. Though, a complete understanding of the polarization of Mn emission is not yet achieved, it can be expected that due to confinement, we observe stronger overlap of wave functions leading to unexpected results.…”

Spin-orbit coupled particle in a spin bath

“…Typically, they are easily synthesized II-VI materials, such as ZnTe, ZnSe, CdS, and CdSe, 91,92 which offer a large size-induced tunability of the transition energies and long spin decoherence times. 93,94 Magnetic doping 95 of these colloidal dots provides an opportunity for a versatile control of magnetic order as well as leads to robust magnetic polaron formation with effective internal magnetic field approaching 100 T. 43,[95][96][97][98][99] …”