We have investigated charge dynamics and electronic structures for single crystals of metallic layered nickelates, R2-xSrxNiO 4 (R=Nd,Eu), isostructural to La2-xSrxCuO 4. Angle-resolved photoemission spectroscopy on the barely metallic Eu0.9Sr1.1NiO4 (R=Eu, x=1.1) has revealed a large hole surface of x2-y2 character with a high-energy pseudogap of the same symmetry and comparable magnitude with those of underdoped (x<0.1) cuprates, although the antiferromagnetic interactions are 1 order of magnitude smaller. This finding strongly indicates that the momentum-dependent pseudogap feature in the layered nickelate arises from the real-space charge correlation.
ASJC Scopus subject areas
- Physics and Astronomy(all)