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Published October 6, 2020 | Supplemental Material + Published + Submitted
Journal Article Open

Magic-angle semimetals

Abstract

Breakthroughs in two-dimensional van der Waals heterostructures have revealed that twisting creates a moiré pattern that quenches the kinetic energy of electrons, allowing for exotic many-body states. We show that cold atomic, trapped ion, and metamaterial systems can emulate the effects of a twist in many models from one to three dimensions. Further, we demonstrate at larger angles (and argue at smaller angles) that by considering incommensurate effects, the magic-angle effect becomes a single-particle quantum phase transition (including in a model for twisted bilayer graphene in the chiral limit). We call these models "magic-angle semimetals". Each contains nodes in the band structure and an incommensurate modulation. At magic-angle criticality, we report a nonanalytic density of states, flat bands, multifractal wave functions that Anderson delocalize in momentum space, and an essentially divergent effective interaction scale. As a particular example, we discuss how to observe this effect in an ultracold Fermi gas.

Additional Information

© The Author(s) 2020. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. Received 02 April 2020. Accepted 09 September 2020. Published 06 October 2020. We thank I. Bloch, P.-Y. Chang, P. Coleman, B.J. DeSalvo, M. Foster, Y. Komijani, G. Pagano, A.M. Rey, M. Schütt, I. Spielman, and D. Vanderbilt for useful discussions. We also thank S. Gopalakrishnan and D. Huse for collaborations on related work and for insightful discussions. J.H.W. and J.H.P. acknowledge the Aspen Center for Physics where some of this work was performed, which is supported by National Science Foundation Grant No. PHY-1607611. J.H.P. is partially supported by the Air Force Office of Scientific Research under Grant No. FA9550-20-1-0136. E.J.K. was supported by the U.S. Department of Energy, Basic Energy Sciences, grant number DE-FG02-99ER45790. This work was supported by the Caltech Institute for Quantum Information and Matter, an NSF Physics Frontiers Center with support of the Gordon and Betty Moore Foundation and the Air Force Office for Scientific Research (J.H.W.). Y.-Z.C. was supported in part by a Simons Investigator award to Leo Radzihovsky and in part by the Army Research Office under Grant Number W911NF-17-1-0482. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the Army Research Office or the U.S. Government. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation herein. The authors acknowledge the Beowulf cluster at the Department of Physics and Astronomy of Rutgers University, The State University of New Jersey, and the Office of Advanced Research Computing (OARC) at Rutgers, The State University of New Jersey (http://oarc.rutgers.edu) for providing access to the Amarel cluster and associated research computing resources that have contributed to the results reported here. These authors contributed equally: Yixing Fu, Elio J. König, Justin H. Wilson. Author Contributions. E.J.K., J.H.W., and J.H.P. designed the research, Y.F., E.J.K., J.H.W., Y.-Z.C, and J.H.P. performed the research, and Y.F., E.J.K., J.H.W., Y.-Z.C., and J.H.P. wrote the paper. The authors declare no competing interests.

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Published - s41535-020-00271-9.pdf

Submitted - 1809.04604.pdf

Supplemental Material - 41535_2020_271_MOESM1_ESM.pdf

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Created:
August 19, 2023
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October 20, 2023