We investigate static and dynamic properties of electron spins in the bilayer quantum Hall system at total Landau level filling factor ν = 2 by using current-pumped and resistively detected nuclear magnetic resonance (NMR). The measured Knight shift, KS, of 75As nuclei reveals continuous variation of the out-of-plane electronic spin polarization Pz between nearly full and zero as a function of density imbalance between the two layers. Nuclear spin relaxation rate 1 / T1 indicates that the in-plane spin order accompanied by a gapless low-frequency mode (i.e., the Goldstone mode) develops when Pz varies. These results provide direct information on the spin configuration and the low-energy collective excitations in the canted antiferromagnetic state.
|ジャーナル||Physica E: Low-Dimensional Systems and Nanostructures|
|出版ステータス||Published - 2008 3月|
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