Evidence for pairing above the transition temperature of cuprate superconductors from the electronic dispersion in the pseudogap phase.
In the underdoped high temperature superconductors, instead of a complete Fermi surface above Tc, only disconnected Fermi arcs appear, separated by regions that still exhibit an energy gap. We show that in this pseudogap phase, the energy-momentum relation of electronic excitations near EF behaves like the dispersion of a normal metal on the Fermi arcs, but like that of a superconductor in the gapped regions. We argue that this dichotomy in the dispersion is difficult to reconcile with a competing order parameter, but is consistent with pairing without condensation.
Department of Physics, University of Illinois at Chicago, Chicago, Illinois 60607, USA.
A
A
Kanigel
U
U
Chatterjee
M
M
Randeria
M R
MR
Norman
G
G
Koren
K
K
Kadowaki
J C
JC
Campuzano