Nuclear spin relaxation in the SU(4) spin-pseudospin intertwined skyrmion regime in theν=1bilayer quantum Hall state

Abstract

We investigate the electron spin degree of freedom in imbalanced density $\ensuremath{\nu}=1$ bilayer quantum Hall states using the resistively detected nuclear-spin--lattice relaxation rate $1/{T}_{1}$. The values of $1/{T}_{1}$ in imbalanced states increase rapidly in the vicinity of $\ensuremath{\nu}=1$, similar to the phenomenon that is observed in the region in which skyrmion crystals are formed. Furthermore, the value of $1/{T}_{1}$ in the back layer (the layer from which electrons are transferred to the front layer) also increases in the intermediate imbalanced state. These results indicate that the low-energy electron-spin mode, similar to the mode observed in skyrmion crystals, exists across the two layers. We suggest that such a mode arises in spin-pseudospin intertwined SU(4) skyrmions.