Superconductivity from altermagnetic fluctuations: the crucial role of sublattice polarization
Abstract
Unconventional superconductivity in correlated systems often appears in the vicinity of a magnetically ordered state. This situation is also relevant for altermagnets, characterized by a nonrelativistic spin-split electronic structure in the presence of Néel order. Many proposed altermagnetic candidates, however, never cross the magnetic instability. We study superconductivity arising from altermagnetic fluctuations in such systems and show that the sublattice polarization (SLP) of the normal-state bands plays a pivotal role in determining the superconducting state. SLP, an inherent property of altermagnetic band structures that persists even without magnetic order, prevents Cooper pairs from forming between different sublattices. This suppresses pairing mediated by the nearest-neighbor antiferromagnetic exchange, which favors spin-singlet superconductivity, and leaves longer-range same-sublattice bonds dominant. When the next-nearest-neighbor exchange is ferromagnetic, as expected for frustration-free Néel order, this results in spin-triplet superconductivity. This mechanism is fundamentally different from that in altermagnets with long-range Néel order, where the spin-split Fermi surfaces favor equal-spin pairing. Finally, when longer-range interactions in the disordered phase instead favor singlet pairing, SLP leads to singlet states with characteristic properties distinct from nearest-neighbor pairing states.
Related
- Altermagnetic Control of Charge-4e Superconductivity
- Topological superconductivity in layered d-wave altermagnetic metals
- Phonon Fluctuations Enhanced Superconductivity in a Three-Band Cuprate Model
- Quantum phase fluctuations quench chiral superconductivity in twisted overdoped cuprate bilayers
- Phase fluctuations dominated superconductivity in a thick Granular Boron-Doped Diamond film
BibTeX
@misc{barkman2026superconductivity,
title = {{Superconductivity from altermagnetic fluctuations: the crucial role of sublattice polarization}},
author = {Mats Barkman and Andreas Kreisel and Brian M. Andersen},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.16507},
eprint = {2610.16507},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.16507},
}
RIS
TY - UNPB
TI - Superconductivity from altermagnetic fluctuations: the crucial role of sublattice polarization
AU - Mats Barkman
AU - Andreas Kreisel
AU - Brian M. Andersen
PY - 2026
DA - 2026/10/12
PB - arXiv
DO - 10.48550/arxiv.2610.16507
UR - https://arxiv.org/abs/2610.16507
AB - Unconventional superconductivity in correlated systems often appears in the vicinity of a magnetically ordered state. This situation is also relevant for altermagnets, characterized by a nonrelativistic spin-split electronic structure in the presence of Néel order. Many proposed altermagnetic candidates, however, never cross the magnetic instability. We study superconductivity arising from altermagnetic fluctuations in such systems and show that the sublattice polarization (SLP) of the normal-state bands plays a pivotal role in determining the superconducting state. SLP, an inherent property of altermagnetic band structures that persists even without magnetic order, prevents Cooper pairs from forming between different sublattices. This suppresses pairing mediated by the nearest-neighbor antiferromagnetic exchange, which favors spin-singlet superconductivity, and leaves longer-range same-sublattice bonds dominant. When the next-nearest-neighbor exchange is ferromagnetic, as expected for frustration-free Néel order, this results in spin-triplet superconductivity. This mechanism is fundamentally different from that in altermagnets with long-range Néel order, where the spin-split Fermi surfaces favor equal-spin pairing. Finally, when longer-range interactions in the disordered phase instead favor singlet pairing, SLP leads to singlet states with characteristic properties distinct from nearest-neighbor pairing states.
ER -