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arXiv · 2406.16277

Spinon pairing induced by chiral in-plane exchange and the stabilization of odd-spin Chern number spin liquid in twisted ${\rm MoTe}_2$

Valentin Crépel·Andrew Millis
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Abstract

The unusual structure and symmetry of low-energy states in twisted transition metal dichalcogenides leads to large in-plane spin-exchange interactions between spin-valley locked holes. We demonstrate that this exchange interaction can stabilize a gapped spin-liquid phase with a quantized spin-Chern number of three when the twist angle is sufficiently small and the system lies in a Mott insulating phase. The gapped spin liquid may be understood as arising from spinon pairing in the DIII Altland-Zirnbauer symmetry class. Applying an out of plane electric field or increasing the twist angle is shown to drive a transition respectively to an anomalous Hall insulator or an in-plane antiferromagnet. Recent experiments indicate that a spin-Chern number three phase occurs in twisted MoTe$_2$ at small twist angles with a transition to a quantum anomalous Hall phase as the twist angle is increased above a critical value of about $2.5^\circ$ in absence of applied electric field.

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Valentin Crépel, Andrew Millis. 2024-06-24. Spinon pairing induced by chiral in-plane exchange and the stabilization of odd-spin Chern number spin liquid in twisted ${\rm MoTe}_2$. https://doi.org/10.1103/physrevlett.133.146503

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