Exchange splitting and exchange-induced nonreciprocal photonic behavior of graphene in CrI3 -graphene van der Waals heterostructures

Gate-Tunable Proximity Effects in Graphene on Layered Magnetic Insulators

“…We estimate this to be ∼25 meV from the fact that the ν = −2 state fully develops at B ≈ 0.5 T (Figure c), following the expectation that the corresponding cyclotron gap is normalΔ E − 2 = v normalF 2 ℏ normale italicB , where v F = 10 6 m/s is the presumed Fermi velocity of graphene and ℏ is Planck’s reduced constant. This is in tension with theoretical predictions of magnetic exchange couplings ranging from tens of meV to as large as ∼120 meV in graphene on CrI 3 . − Furthermore, unambiguous evidence for a proximity exchange field has been observed in optical spectroscopy measurements of monolayer WSe 2 on a CrI 3 substrate. , The apparent unexpectedly small exchange coupling for graphene on CrI 3 may be intrinsic, but it may also be degraded by disorder in the CrI 3 for reasons that are not clear at present. Progress toward a high-temperature quantum anomalous Hall effect in proximitized graphene will likely require a reduction of the defect concentration in the CrI 3 crystal or the discovery of more favorable magnetic insulator substrates.…”

Quantum anomalous Hall effect in germanene by proximity coupling to a semiconducting ferromagnetic substrate NiI2

“…Meanwhile, the band of ML-NiI 2 shifts downward by 19.1 meV near the E F in the spin-up channel. These results show that the Ge/NiI 2 HTS has a stronger interlayer vdW interaction than other vdW HTSs, such as phosphorene/graphene, 33 InSe/phosphorene, 34 graphene/CrI 3 , 35 and so on. Hence, spin-polarized charges transfer between the germanene and NiI 2 layers, inducing spin-up electron and spin-down hole doping for ML-NiI 2 and germanene, respectively.…”

Spin-orbit correlations and exchange-bias control in twisted Janus dichalcogenide multilayers

“…While usually boron-nitride encapsulation is used, other different insulators can be considered. In particular, the use of van der Waals ferromagnetic insulators [58][59][60] such as CrCl 3 61 , CrBr 3 62 , and CrI 3 63 as encapsulation [64][65][66][67][68] pro- vide an interesting possibility with regards to controlling a correlated state in the twisted Janus bilayer. We now will show how a magnetic encapsulation allows controlling the underlying electronic structure of the Janus system, and in particular, tuning the non-collinear magnetic order of the correlated state.…”