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arXiv · 2610.34315

Tilt-Controlled Multi-Gap Superconductivity in Type-II Weyl Semimetals

Mingyu Lee·Myungjun Kang·Sangmo Cheon
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Abstract

In type-II Weyl semimetals, strongly tilted Weyl cones produce coexisting electron and hole pockets, a natural multi-band setting for superconductivity, yet how the tilt controls the number and relative size of the superconducting gaps remains unclear. Here we classify the symmetry-allowed on-site pairing channels of a simple time-reversal symmetric tilted Weyl-semimetal model with $D_4$ symmetry and identify the fully symmetric $A_1$ channel as the leading instability for attractive on-site interactions, supporting a fully gapped two-gap state. The tilt acts as a microscopic control parameter, redistributing the band-resolved pairing susceptibility between the two Fermi-surface sectors rather than simply rescaling the total density of states. Once the tilt sufficiently enhances the secondary channel, a robust secondary gap develops and can exceed the primary gap even at weaker effective coupling, while inter-gap coupling locks both gaps to a common critical superconducting temperature. The Weyl cone tilt thus controls the emergence and hierarchy of multi-gap superconductivity.

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Mingyu Lee, Myungjun Kang, Sangmo Cheon. 2026-10-25. Tilt-Controlled Multi-Gap Superconductivity in Type-II Weyl Semimetals. https://arxiv.org/abs/2610.34315

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