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Fabricating van der Waals Heterostructures with Precise Rotational Alignment
Published on: July 5, 2019
Anti-topological crystal and non-Abelian liquid in twisted semiconductor bilayers
Aidan P Reddy1, D N Sheng2, Ahmed Abouelkomsan1
1Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
None:
We show that electron crystals compete closely with non-Abelian fractional Chern insulators in the half-filled second moiré band of twisted bilayer MoTe2. Depending on the twist angle and microscopic model, these crystals can have non-zero or zero Chern numbers C. The C = 0 crystal occurs because contributions to the total Chern number from the full first band (+1) and half-full second band (-1) cancel. This is counterintuitive because the first two non-interacting bands in a given valley have the same Chern number + 1. For these two reasons, we call this crystal an anti-topological crystal. The anti-topological crystal is a novel type of electron crystal that may occur in systems with multiple Chern bands at filling factors n > 1.
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