Effects of magnetic order on the upper critical field of UPt{sub 3}
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208 (United States)
I present a Ginzburg-Landau theory for hexagonal oscillations of the upper critical field of UPt{sub 3} near {ital T}{sub {ital c}}. The model is based on a two-dimensional representation for the superconducting order parameter, {eta}{searrow}=({eta}{sub 1},{eta}{sub 2}), coupled to an in-plane antiferromagnetic (AFM) order parameter, {ital m}{searrow}{sub {ital s}}. Hexagonal anisotropy of {ital H}{sub {ital c}2} arises from the weak in-plane anisotropy energy of the AFM state and the coupling of the superconducting order parameter to the staggered field. The model explains the important features of the observed hexagonal anisotropy [N. Keller {ital et} {ital al}., Phys. Rev. Lett. {bold 73}, 2364 (1994)] including (i) the small magnitude, (ii) persistence of the oscillations for {ital T}{r_arrow}{ital T}{sub {ital c}}, and (iii) the change in sign of the oscillations for {ital T}{approx_gt}{ital T}{sup {asterisk}} and {ital T}{lt}{ital T}{sup {asterisk}} (the temperature at the tetracritical point). I also show that there is a low-field crossover (observable only very near {ital T}{sub {ital c}}) below which the oscillations should vanish. {copyright} {ital 1996 The American Physical Society.}
- OSTI ID:
- 279802
- Journal Information:
- Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 13 Vol. 53; ISSN PRBMDO; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
Similar Records
Staggered superconductivity in UPt{sub 3}: A new phenomenological approach
Thermodynamic stability of the superconducting phase diagram of UPt[sub 3]