The superconducting states, corresponding to d(k)
= (k+
_{x
}ik)
(left) and
_{y}d(k) = k+ _{x
}k
(right), have different spin orientations and total angular momentum.
The (_{y}k+ _{x
}ik) state has
an angular momentum along the _{y}z-axis (thick arrow) and spin perpendicular
in the plane (thin arrows). Its total angular momentum therefore
has a value of 1 and points along the z-axis. The k+ _{x
}k
state has vanishing total angular momentum because the orbital angular
momentum is compensated by the spins of the Cooper pair. Both states
represent equal-spin-pairing states, but have very different physical properties.
Experiments identify the superconducting phase in Sr_{y}_{2}RuO_{4}
as being of the type in the left panel--that is, a state with finite angular
momentum.
© 2001 American Institute of Physics |

Strontium ruthenate |