Coupled superconducting and magnetic order in CeCoIn5.
Strong magnetic fluctuations can provide a coupling mechanism for electrons that leads to unconventional superconductivity. Magnetic order and superconductivity have been found to coexist in a number of magnetically mediated superconductors, but these order parameters generally compete. We report that close to the upper critical field, CeCoIn5 adopts a multicomponent ground state that simultaneously carries cooperating magnetic and superconducting orders. Suppressing superconductivity in a first-order transition at the upper critical field leads to the simultaneous collapse of the magnetic order, showing that superconductivity is necessary for the magnetic order. A symmetry analysis of the coupling between the magnetic order and the superconducting gap function suggests a form of superconductivity that is associated with a nonvanishing momentum.
Kenzelmann
M
M
Laboratory for Developments and Methods, Paul Scherrer Institute, CH-5232 Villigen, Switzerland.
Strässle
T
T
Niedermayer
C
C
Sigrist
M
M
Padmanabhan
B
B
Zolliker
M
M
Bianchi
A D
AD
Movshovich
R
R
Bauer
E D
ED
Sarrao
J L
JL
Thompson
J D
JD