Zhou, H.; Polshyn, HryhoriyISTA ; Taniguchi, T.; Watanabe, K.; Young, A. F.
Partially filled Landau levels host competing electronic orders. For example, electron solids may prevail close to integer filling of the Landau levels before giving way to fractional quantum Hall liquids at higher carrier density1,2. Here, we report the observation of an electron solid with non-collinear spin texture in monolayer graphene, consistent with solidification of skyrmions3—topological spin textures characterized by quantized electrical charge4,5. We probe the spin texture of the solids using a modified Corbino geometry that allows ferromagnetic magnons to be launched and detected6,7. We find that magnon transport is highly efficient when one Landau level is filled (ν=1), consistent with quantum Hall ferromagnetic spin polarization. However, even minimal doping immediately quenches the magnon signal while leaving the vanishing low-temperature charge conductivity unchanged. Our results can be understood by the formation of a solid of charged skyrmions near ν=1, whose non-collinear spin texture leads to rapid magnon decay. Data near fractional fillings show evidence of several fractional skyrmion solids, suggesting that graphene hosts a highly tunable landscape of coupled spin and charge orders.
We acknowledge discussions with B. Halperin, C. Huang, A. Macdonald and M. Zalatel. Experimental work at UCSB was supported by the Army Research Office under awards nos. MURI W911NF-16-1-0361 and W911NF-16-1-0482. K.W. and T.T. acknowledge support from the Elemental Strategy Initiative conducted by MEXT (Japan) and CREST (JPMJCR15F3), JST. A.F.Y. acknowledges the support of the David and Lucile Packard Foundation and and Alfred. P. Sloan Foundation.
Zhou H, Polshyn H, Taniguchi T, Watanabe K, Young AF. Solids of quantum Hall skyrmions in graphene. Nature Physics. 2019;16(2):154-158. doi:10.1038/s41567-019-0729-8
Zhou, H., Polshyn, H., Taniguchi, T., Watanabe, K., & Young, A. F. (2019). Solids of quantum Hall skyrmions in graphene. Nature Physics. Springer Nature. https://doi.org/10.1038/s41567-019-0729-8
Zhou, H., Hryhoriy Polshyn, T. Taniguchi, K. Watanabe, and A. F. Young. “Solids of Quantum Hall Skyrmions in Graphene.” Nature Physics. Springer Nature, 2019. https://doi.org/10.1038/s41567-019-0729-8.
H. Zhou, H. Polshyn, T. Taniguchi, K. Watanabe, and A. F. Young, “Solids of quantum Hall skyrmions in graphene,” Nature Physics, vol. 16, no. 2. Springer Nature, pp. 154–158, 2019.
Zhou H, Polshyn H, Taniguchi T, Watanabe K, Young AF. 2019. Solids of quantum Hall skyrmions in graphene. Nature Physics. 16(2), 154–158.
Zhou, H., et al. “Solids of Quantum Hall Skyrmions in Graphene.” Nature Physics, vol. 16, no. 2, Springer Nature, 2019, pp. 154–58, doi:10.1038/s41567-019-0729-8.