9 research outputs found
Kondo Physics in a Rare Earth Ion with Well Localized 4f Electrons
Dilute Nd in simple cubic LaB shows electrical resistance and specific
heat features at low temperature consistent with a Kondo scale of 0.3 K. Nd has a well localized {\it 4f} {\it J} = 9/2 Hund's
Rule configuration which is not anticipated to be Kondo coupled to the
conduction electrons in LaB. We conjecture that the unexpected Kondo effect
arises via participation of {\it 4f} quadrupolar degrees of freedom of the Nd
crystal field ground state quartet.Comment: 5 pages, 4 figure
Inhomogeneous LOFF phase revisited for surface superconductivity
We consider 2D surface superconductivity in high magnetic fields parallel to
the surface. We demonstrate that the spin-orbit interaction at the surface
changes the properties of the inhomogeneous superconducting
Larkin-Ovchinnikov-Fulde-Ferrell state that develops above fields given by the
paramagnetic criterion. Strong spin-orbit interaction significantly broadens
the range of existence of the LOFF phase, which takes the form of periodic
superconducting stripes running along the field direction on the surface,
leading to the anisotropy of its properties. In connection with experiments by
J.H. Schon et al. [Nature 914, 434 (2001)] on superconductivity of electrically
doped films of the cuprate material CaCuO2, we also discuss this problem for
the d-wave pairing to indicate the possibility of a re-orientation transition
as the magnetic field direction is rotated in the plane parallel to the
surface. Our results provide a tool for studying surface superconductivity as a
function of doping.Comment: 4 pages, 1 fig, revtex