| mang2004 |
2019-07-27 05:04 |
Emergent ferromagnetism near three-quarters filling in twisted bilayer grapheme yu#Jw
C1p
|.L?m
Abstract &HFMF)NA
F__DPEAc_
When two sheets of graphene are stacked at a small twist angle, the resulting flat superlattice minibands are expected to strongly enhance electron-electron interactions. Here we present evidence that near three-quarters (3/4) filling of the conduction miniband these enhanced interactions drive the twisted bilayer graphene into a ferromagnetic state. In a narrow density range around an apparent insulating state at 3/4, we observe emergent ferromagnetic hysteresis, with a giant anomalous Hall (AH) effect as large as 10.4 kΩ and indications of chiral edge states. Surprisingly, the magnetization of the sample can be reversed by applying a small DC current. Although the AH resistance is not quantized and dissipation is significant, our measurements suggest that the system may be an incipient Chern insulator. >P\T nb"Q\
:U ?P~HI
|
|
