Topological excitons in moiré <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>MoTe</mml:mi> <mml:mn>2</mml:mn> </mml:msub> <mml:mo>/</mml:mo> <mml:msub> <mml:mi>WSe</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:math> heterobilayers
Paul Froese, Titus Neupert, Glenn Wagner
Abstract
Due to the presence of flat Chern bands, moiré transition-metal dichalcogenide (TMD) bilayers are a platform to realize strongly correlated topological phases of fermions such as fractional Chern insulators. TMDs are also known to host long-lived excitons, which inherit the topology of the underlying Chern bands. For the particular example of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"> <a:msub> <a:mi>MoTe</a:mi> <a:mn>2</a:mn> </a:msub> <a:mo>/</a:mo> <a:msub> <a:mi>WSe</a:mi> <a:mn>2</a:mn> </a:msub> </a:math> heterobilayers we perform a time-dependent Hartree-Fock calculation to identify a regime in the phase diagram where the excitons themselves form a topological flat band. This paves a way towards realizing strongly correlated states of bosons in moiré TMDs.