Journal
PHYSICAL REVIEW LETTERS
Volume 128, Issue 17, Pages -Publisher
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevLett.128.176404
Keywords
-
Categories
Funding
- Simons Investigator award
- Simons Collaboration on Ultra-Quantum Matter from the Simons Foundation [651440]
- Department of Defense (DOD) through the National Defense Science and Engineering Graduate Fellowship (NDSEG) Program
Ask authors/readers for more resources
This study considers a family of twisted graphene multilayers and shows that they exhibit similar features to twisted bilayer graphene, including specific "magic angle" positions and ideal quantum geometry. Furthermore, it is found that ideal quantum geometry is closely related to the construction of fractional quantum Hall model wave functions.
We consider a family of twisted graphene multilayers consisting of n-untwisted chirally stacked layers, e.g., AB, ABC, etc, with a single twist on top of m-untwisted chirally stacked layers. Upon neglecting both trigonal warping terms for the untwisted layers and the same sublattice hopping between all layers, the resulting models generalize several remarkable features of the chiral model of twisted bilayer graphene (CTBG). In particular, they exhibit a set of magic angles which are identical to those of CTBG at which a pair of bands (i) are perfectly flat, (ii) have Chern numbers in the sublattice basis given by ??(n, ???m) or ??(n + m ??? 1, ???1) depending on the stacking chirality, and (iii) satisfy the trace condition, saturating an inequality between the quantum metric and the Berry curvature, and thus realizing ideal quantum geometry. These are the first higher Chern bands that satisfy (iii) beyond fine-tuned models or combinations of Landau levels. We show that ideal quantum geometry is directly related to the construction of fractional quantum Hall model wave functions. We provide explicit analytic expressions for the flatband wave functions at the magic angle in terms of the CTBG wave functions. We also show that the Berry curvature distribution in these models can be continuously tuned while maintaining perfect quantum geometry. Similar to the study of fractional Chern insulators in ideal C = 1 bands, these models pave the way for investigating exotic topological phases in higher Chern bands for which no Landau level analog is available.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available