We present a new Ginzburg-Landau theory for superconductivity in ${\mathrm{UPt}}_3$, based upon a multicomponent order parameter transforming under an irreducible space group representation; the phase is staggered in real space. Our model can explain the $H-T-P$ phase diagram including the tetracritical point for all field directions. We motivate this unconventional superconducting state in terms of odd-in-frequency pairing that may arise in one- or two-channel Kondo models, and suggest experimental tests.

• Received 17 August 1994

DOI:https://doi.org/10.1103/PhysRevLett.74.2571