Noncollinear phases in moiré magnets.

We introduce a general framework to study moiré structures of two-dimensional Van der Waals magnets using continuum field theory. The formalism eliminates quasi periodicity and allows a full understanding of magnetic structures and their excitations. In particular, we analyze in detail twisted bi layers of N ́eelantiferromagnets on the honeycomb lattice. A rich phase diagram with noncollinear twisted phases is obtained, and spin waves are further calculated. Direct extensions to zigzag anti-ferromagnets and ferromagnets are also presented. We anticipate the results and formalism demonstrated to lead to abroad range of applications to both fundamental research and experiments. [ABSTRACT FROM AUTHOR]