Twist engineering of the two-dimensional magnetism in double bilayer chromium triiodide homostructures

Hongchao Xie, Xiangpeng Luo, Gaihua Ye, Zhipeng Ye, Haiwen Ge, Suk Hyun Sung, Emily Rennich, Shaohua Yan, Yang Fu, Shangjie Tian, Hechang Lei, Robert Hovden, Kai Sun, Rui He, Liuyan Zhao

Research output: Contribution to journalArticlepeer-review

Abstract

Twist engineering—the alignment of two-dimensional (2D) crystalline layers with a specific orientation—has led to tremendous success in controlling the charge degree of freedom, particularly in producing correlated and topological electronic phases in moiré crystals1,2. However, although pioneering theoretical efforts have predicted that non-trivial magnetism3–5 and magnons6,7 can be made by twisting 2D magnets, the experimental realization of engineering the spin degree of freedom by twisting remains elusive. Here we fabricate twisted double bilayers of a 2D magnet, namely, chromium triiodide (CrI3), and demonstrate the successful twist engineering of 2D magnetism in them. We identify signatures of a new magnetic ground state that is distinct from those in natural two-layer (2L) and four-layer (4L) CrI3. We show that for a very small twist angle, this emergent magnetism can be well approximated by a weighted linear superposition of those of 2L and 4L CrI3, whereas for a large twist angle, it mostly resembles that of isolated 2L CrI3. However, at an intermediate twist angle, there is a finite net magnetization that cannot be simply inferred from any homogeneous stacking configuration, but emerges because spin frustrations are introduced by competition between ferromagnetic and antiferromagnetic exchange coupling within individual moiré supercells.

Original languageEnglish
Pages (from-to)30-36
Number of pages7
JournalNature Physics
Volume18
Issue number1
DOIs
StatePublished - Jan 2022

Fingerprint

Dive into the research topics of 'Twist engineering of the two-dimensional magnetism in double bilayer chromium triiodide homostructures'. Together they form a unique fingerprint.

Cite this