Fig. 3: Electronic structure and NAHE of bilayer WTe2.
From: Ferroelectric nonlinear anomalous Hall effect in few-layer WTe2
a Band structure of bilayer WTe2 in ±mFE state color-coded by the z-component of intraband Berry curvature \({\mathrm{\Omega }}_n^z\left( {\boldsymbol{k}} \right)\). Spin-orbit coupling is included and hybrid HSE06 functional is employed. b BCD and SD tensor elements \(D_{yz}^{{\mathrm{intra}}}\left( \mu \right)\), \(D_{yz}^{{\mathrm{C}},{\mathrm{inter}}}\left( {\mu ,\omega } \right)\), and \(D_{xy}^{{\mathrm{L}},{\mathrm{inter}}}\left( {\mu ,\omega } \right)\) as function of chemical potential μ. For interband BCD and SD, ω is set to 120 meV. c, d k-dependent distribution of intraband Berry curvature \({\mathrm{\Omega }}_{{\mathrm{occ}}}^{z,{\mathrm{intra}}}\left( {\boldsymbol{k}} \right)\) at μ = ±50 meV, respectively. e, f k-dependent distribution interband Berry curvature \({\mathrm{\Omega }}_{nm}^{z,{\mathrm{inter}}}\left( {\boldsymbol{k}} \right)\) for (n, m) = (VBM-1, CBM) and for (n, m) = (VBM-1, CBM), respectively. The results are the same for both +mFE and −mFE state, suggesting that nonlinear anomalous Hall current can be induced in bilayer WTe2, but it will not switch sign upon ferroelectric transition.
