  Single crystal antiferromagnetic USb2 was studied at 15K by angle-resolved
photoemission with an overall energy resolution of 24 meV. The measurements
unambiguously show the dispersion of extremely narrow bands situated near the
Fermi level. The peak at the Fermi level represents the narrowest feature
observed in 5f-electron photoemission to date. The natural linewidth of the
feature just below the Fermi level is not greater than 10 meV. Normal emission
data indicate a three dimensional aspect to the electronic structure of this
layered material.
