Resistively Detected Nuclear Magnetic Resonance (RD-NMR) has been used to investigate a two-subband electron system in a regime where quantum Hall pseudo-spin ferromagnetic (QHPF) states are prominently developed. It reveals that the easy-axis QHPF state around the total filling factor ν=4 can be detected by the RD-NMR measurement. Approaching one of the Landau level (LL) crossing points, the RD-NMR signal strength and the nuclear spin relaxation rate 1/T1 enhance significantly, a signature of low energy spin excitations. However, the RD-NMR signal at another identical LL crossing point is surprisingly missing which presents a puzzle.
@article{arxiv.0904.0917,
title = {Probing Quantum Hall Pseudospin Ferromagnet by Resistively Detected NMR},
author = {G. P. Guo and Y. J. Zhao and T. Tu and X. J. Hao and G. C. Guo and H. W. Jiang},
journal= {arXiv preprint arXiv:0904.0917},
year = {2015}
}