A. B. Andrews

Electronic structure of heavy fermions: Narrow temperature-independent bands☆

The electronic structure of both Ce and U heavy fermions appears to consist of extremely narrow temperature independent bands. There is no evidence from photoemission for a collective phenomenon normally referred to as the Kondo resonance. In uranium compounds a small dispersion of the bands is easily measurable.

The 5f band structure of antiferromagnetic USb2 from angle-resolved photoemission spectroscopy: Application to heavy fermions

We show the first direct observation of 5f band dispersion in an antiferromagnetic 5f compound, USb2, closely related to heavy fermions.

4f bands in Ce heavy fermions and mixed valent compounds at T ⪢ TK

Abstract We report evidence of 4f band character in Ce 4f states at T ⪢ T K using high-resolution angle-resolved resonant photoemission. The Ce intermetallic compound CePt 2+ x was grown and studied in situ by the method of MBE and was characterized by LEED, XPS and XAS. These new findings suggest a need for a re-examination of 4f photoemission in Ce compounds.

Temperature dependence of 4f PES features and hole occupancy in yterbium heavy fermions

Abstract We have measured the temperature dependence between 80 and 300 K and spectral weight of the 4f features in clean single crystal Yb heavy fermions, cleaved in a vacuum of 5 × 10−11 Torr. A small (∼ 15%) decrease in spectral weight differs substantially from the reported ∼ 50% decrease over this range. All divalent features are much larger than expected, yielding nf values far too small. The intensity of the divalent features in YbAuCu4 is about two orders of magnitude larger than expected.