article
Topological charge density waves at half-integer filling of a moiré superlattice
published
yes
Hryhoriy
Polshyn
author edfc7cb1-526e-11ec-b05a-e6ecc27e4e480000-0001-8223-8896
Y.
Zhang
author
M. A.
Kumar
author
T.
Soejima
author
P.
Ledwith
author
K.
Watanabe
author
T.
Taniguchi
author
A.
Vishwanath
author
M. P.
Zaletel
author
A. F.
Young
author
When a flat band is partially filled with electrons, strong Coulomb interactions between them may lead to the emergence of topological gapped states with quantized Hall conductivity. Such emergent topological states have been found in partially filled Landau levels1 and Hofstadter bands2,3; however, in both cases, a large magnetic field is required to produce the underlying flat band. The recent observation of quantum anomalous Hall effects in narrow-band moiré materials4,5,6,7 has led to the theoretical prediction that such phases could be realized at zero magnetic field8,9,10,11,12. Here we report the observation of insulators with Chern number C = 1 in the zero-magnetic-field limit at half-integer filling of the moiré superlattice unit cell in twisted monolayer–bilayer graphene7,13,14,15. Chern insulators in a half-filled band suggest the spontaneous doubling of the superlattice unit cell2,3,16, and our calculations find a ground state of the topological charge density wave at half-filling of the underlying band. The discovery of these topological phases at fractional superlattice filling enables the further pursuit of zero-magnetic-field phases that have fractional statistics that exist either as elementary excitations or bound to lattice dislocations.
Springer Nature2021
eng
general physicsastronomy
Nature Physics
1745-2473
1745-2481
2104.0117810.1038/s41567-021-01418-6
yes
Polshyn, Hryhoriy, et al. “Topological Charge Density Waves at Half-Integer Filling of a Moiré Superlattice.” <i>Nature Physics</i>, Springer Nature, 2021, doi:<a href="https://doi.org/10.1038/s41567-021-01418-6">10.1038/s41567-021-01418-6</a>.
H. Polshyn <i>et al.</i>, “Topological charge density waves at half-integer filling of a moiré superlattice,” <i>Nature Physics</i>. Springer Nature, 2021.
Polshyn H, Zhang Y, Kumar MA, Soejima T, Ledwith P, Watanabe K, Taniguchi T, Vishwanath A, Zaletel MP, Young AF. 2021. Topological charge density waves at half-integer filling of a moiré superlattice. Nature Physics.
Polshyn H, Zhang Y, Kumar MA, et al. Topological charge density waves at half-integer filling of a moiré superlattice. <i>Nature Physics</i>. 2021. doi:<a href="https://doi.org/10.1038/s41567-021-01418-6">10.1038/s41567-021-01418-6</a>
Polshyn, Hryhoriy, Y. Zhang, M. A. Kumar, T. Soejima, P. Ledwith, K. Watanabe, T. Taniguchi, A. Vishwanath, M. P. Zaletel, and A. F. Young. “Topological Charge Density Waves at Half-Integer Filling of a Moiré Superlattice.” <i>Nature Physics</i>. Springer Nature, 2021. <a href="https://doi.org/10.1038/s41567-021-01418-6">https://doi.org/10.1038/s41567-021-01418-6</a>.
Polshyn, H., Zhang, Y., Kumar, M. A., Soejima, T., Ledwith, P., Watanabe, K., … Young, A. F. (2021). Topological charge density waves at half-integer filling of a moiré superlattice. <i>Nature Physics</i>. Springer Nature. <a href="https://doi.org/10.1038/s41567-021-01418-6">https://doi.org/10.1038/s41567-021-01418-6</a>
H. Polshyn, Y. Zhang, M.A. Kumar, T. Soejima, P. Ledwith, K. Watanabe, T. Taniguchi, A. Vishwanath, M.P. Zaletel, A.F. Young, Nature Physics (2021).
106172022-01-13T12:30:47Z2022-01-13T14:11:31Z