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Accepted · first revision · record

Title: Can electron interactions alone produce altermagnetism?
Plain: Known altermagnets get their spin splitting from the arrangement of atoms in the crystal. Theory suggests that repulsion between electrons could create the same kind of spin-split state spontaneously, but no unbiased calculation has shown it in a simple model.
Precise: Find a lattice model of interacting electrons (for example an extended Hubbard model with on-site U and nearest-neighbor V) whose paramagnetic phase has no symmetry-inequivalent magnetic sublattices and whose ground state spontaneously develops a d-wave or g-wave spin-split Fermi surface with zero net magnetization, established by unbiased numerics (DMRG, auxiliary-field quantum Monte Carlo or tensor networks) beyond mean-field theory. An answer is the model, the parameter range and the order parameter.
Settled by: An unbiased ground-state calculation with finite-size extrapolation of the spin-split order parameter in the proposed model.
Kind: well-posed
Answer type: yes-no
References: (empty)
Literature status: open
Status note: (empty)
Posed since: (empty)