## CMT54

##
A Theory of the Superconducting Phases of UPt_{3}

**Author(s):**
J. A. Sauls

**Comments:**
12 pages with 5 figures

**Journal:**
J. Low Temp. Phys. 95, 153 (1994)
[DOI]

**Abstract:**
I discuss a phenomenological theory for the multiple superconducting phases of UPt_{3}
that is based on an order parameter belonging to an orbital 2D representation of the hexagonal
point group which is coupled to a weak symmetry breaking field. I show that (1) the existing H-T
and P-T phase diagrams (including an apparent tetracritical point in the H-T plane for all field
orientations), (2) the anisotropy of the upper critical field over the full temperature range,
(3) the correlation between superconductivity and basal plane antiferromagnetism and (4) low-temperature
power laws in the transport and thermodynamic properties can be explained qualitatively, and in many
respects quantitatively, by an odd-parity, E_{2u} order parameter with a pair spin projection
of zero along the c-axis. AFM ordering in the basal plane, which couples to the superconducting
order parameter, acts as the symmetry breaking field that is responsible for
both the apparent tetracritical point and the zero-field double transition.