Spin-pseudospin intertwined excitation at the ν = 1 bilayer quantum Hall state investigated by nuclear-spin relaxation

Abstract

We investigate the electron spin degree of freedom at the imbalanced density bilayer ν = 1 quantum Hall states using the resistively detected nuclear-spin-lattice relaxation rate 1/T 1 . Our measurements reveal a continuous change in 1/T 1 for σ = 1 to 0, suggesting that the balanced density ν = 1 state also exhibits electron-spin fluctuations. Moreover, the value of 1/T 1 in the back layer (the layer from which electrons are transferred to the front layer) increases at intermediate density imbalance states. This indicates that the low-energy electron-spin mode, similar to a mode observed in Skyrmion crystals, might extend across the two layers.