Fig. 3: Berry curvature dipole with different strain and displacement fields.
From: Nonlinear Hall effects in strained twisted bilayer WSe2
a The Vz(out of plane displacement field) and nh(number of holes per unit cell) dependence of Dx(x component Berry dipole) with strain ϵ = 0.5% along the zigzag edge direction. The color bar shows the magnitude of Dx. The critical Vz at which the phase transition occurs is denoted by the horizontal dashed line. Dx is strongly enhanced near the phase transition point and nh ≈ 2 when the Fermi energy is near the bottom of the top valence band. b Dx, Dy as a function of Vz with fixed nh. The values of nh ( = 1.95) are denoted by the vertical line 1 in a. For b, an uniaxial strain is applied along the zigzag edge direction. c Same parameters as b but the uniaxial strain is applied along the armchair edge direction. d, e The Berry curvatures Ω of top valence band of strained tWSe2 in the deformed Brillouin zone before and after the topological phase transition respectively. In d, Vz = 3 meV, in e, Vz = 5 meV. The strain is applied along the zigzag edge direction. The temperature is set to 1.5K.
