Correlation-enhanced spin–orbit coupling in a quantum anomalous Hall insulator Fe₂Br₂ monolayer with a large band gap and robust ferromagnetism

Abstract

Nontrivial band topology combined with magnetic ordering can produce quantum anomalous Hall insulator (QAHI), which may lead to advances in device concepts. Here, through first-principles calculations, stable monolayer $\mathrm{Fe_2Br_2}$ is...

Temperature-dependent magnetic properties of the room-temperature ferromagnetic Janus monolayer Fe2XY (X, Y = I, Br, Cl; X ≠ Y)

“…18,19 Numerous theoretical studies confirmed that these Janus monolayer materials have great potential for applications in optoelectronic, 20,21 photocatalytic, 22,23 spintronic, [24][25][26] thermoelectric, 27,28 piezoelectric, [29][30][31][32] and valleytronic 33 devices. Recently, inspired by the prediction that Fe 2 X 2 (X = I or Br) monolayers are room-temperature ferromagnets 34,35 with excellent carrier mobility, tunable perpendicular magnetic anisotropy, graphene-like Dirac bands and exotic topological phases, Guo et al investigated the Janus monolayers Fe 2 IY (Y = Cl and Br) and theoretically confirmed that they are piezoelectric quantum anomalous Hall insulators (PQAHI) resulting from inversion symmetry breaking. 36 Furthermore, Fe 2 I 1−x Br x (x = 0.25 or 0.75) monolayers with M x and M y mirror symmetries were confirmed to preserve the topological properties.…”

Excellent intrinsic Chern insulators: monolayer PdTaX2 (X = Se, Te)

“…7(b) displays the collection of band gaps of previously reported 2D QAHE materials. 13,23,62–69 The results indicate that the SOC induced global band gap of PdTaTe 2 (566 meV) is the largest one (the 798 meV band gap is not global one 69 ) in the ferromagnetic Chern insulators reported to date. A detailed comparison can also be found in Table S2 (ESI†).…”

“…Moreover, edge states of PdTaX 2 (X = Se, Te) are totally spin-polarized, and they are also potential candidate for spintronics. For more comparison, we collect T c values from previously synthesized and theoretically predicted 2D Chern insulators, 13,23,[62][63][64][65][66][67][68] especially those belonging to the same tetragonal crystal structure, 13,23,[66][67][68] and the monolayers we proposed, the comparison is presented in Fig. 7(a).…”