Twisted bilayer MoTe2 (tMoTe2) has emerged as a robust platform for exploring correlated topological phases, notably supporting fractional Chern insulator (FCI) states at zero magnetic field across a wide range of twist angles. The evolution of magnetism and topology with twist angle remains an open question. Here, we systematically map the magnetic phase diagram of tMoTe2 using local optical spectroscopy and scanning nanoSQUID-on-tip (nSOT) magnetometry. We identify spontaneous ferromagnetism at moir\'e filling factors ν=−1 and −3 over a twist angle range from 2.1∘ to 3.7∘, revealing a universal, twist-angle-insensitive ferromagnetic phase. At 2.1∘, we further observe robust ferromagnetism at ν=−5, absent in the devices with larger twist angle -- a signature of the flattening of higher bands in this twist angle range. Temperature-dependent measurements reveal a contrasting twist-angle dependence of the Curie temperatures between ν=−1 and ν=−3, indicating distinct interplay between exchange interaction and bandwidth for the two Chern bands. Despite spontaneous time-reversal symmetry breaking, we find no evidence of a topological gap at ν=−3; however, fragile correlated topological phases could be obscured by the device disorder evident in our spatially resolved measurements. Our results establish a global framework for understanding and controlling magnetic order in tMoTe2 and highlight its potential for accessing correlated topological phases in higher energy Chern band.
@article{arxiv.2507.22354,
title = {Universal Magnetic Phases in Twisted Bilayer MoTe$_2$},
author = {Weijie Li and Evgeny Redekop and Christiano Wang Beach and Canxun Zhang and Xiaowei Zhang and Xiaoyu Liu and Will Holtzmann and Chaowei Hu and Eric Anderson and Heonjoon Park and Takashi Taniguchi and Kenji Watanabe and Jiun-haw Chu and Liang Fu and Ting Cao and Di Xiao and Andrea F. Young and Xiaodong Xu},
journal= {arXiv preprint arXiv:2507.22354},
year = {2025}
}