Nonlinear Hall effects in strained twisted bilayer WSe2

Abstract Recently, it has been pointed out that the twisting of bilayer WSe 2 would generate topologically non-trivial flat bands near Fermi energy. In this work, we show twisted (tWSe ) with uniaxial strain exhibits a large nonlinear Hall (NLH) response due to Berry curvatures bands. Moreover, NLH effect is greatly enhanced topological phase transition point which can be tuned by vertical displacement field. Importantly, signal changes sign across and provides way identify probe properties The strong enhancement high tunability renders tWSe related moire materials available platforms for rectification second harmonic generations.