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arXiv · 2503.14721

Quantum Geometric Helical Superconductivity

Aaron Dunbrack·Pauli Virtanen·Tero T. Heikkilä
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Abstract

Several physical phenomena in superconductors, such as helical superconductivity and the diode effect, rely on breaking time-reversal symmetry. This symmetry-breaking is usually accounted for via the Lifshitz invariant, a contribution to the free energy which is linear in the phase gradient of the order parameter. In dispersive single-band superconductors with conventional pairing, the Lifshitz invariant can be computed from the asymmetries of the spectrum near the Fermi surface. We show that in multi-band superconductors, the quantum geometry also contributes to the Lifshitz invariant, and this is the dominant contribution when the low-energy bands are flat. We also analogously demonstrate quantum-geometry-driven commensurate-incommensurate transitions in charge and pair density waves.

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Aaron Dunbrack, Pauli Virtanen, Tero T. Heikkilä. 2025-03-18. Quantum Geometric Helical Superconductivity. https://doi.org/10.1103/wnm6-rf2v

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