%0 Journal Article
%T Camelback-shaped band reconciles heavy electron behavior with weak electronic Coulomb correlations in superconducting TlNi2Se2
%A N. Xu
%A C. E. Matt
%A P. Richard
%A A. van Roekeghem
%A S. Biermann
%A X. Shi
%A S. -F. Wu
%A H. W. Liu
%A D. Chen
%A T. Qian
%A N. C. Plumb
%A M. Radovic
%A Hangdong Wang
%A Qianhui Mao
%A Jianhua Du
%A Minghu Fang
%A J. Mesot
%A H. Ding
%A M. Shi
%J Physics
%D 2014
%I arXiv
%R 10.1103/PhysRevB.92.081116
%X Using high-resolution photoemission spectroscopy and first-principles calculations, we characterize superconducting TlNi$_2$Se$_2$ as a material with weak electronic Coulomb correlations leading to a bandwidth renormalization of 1.4. We identify a camelback-shaped band, whose energetic position strongly depends on the selenium height. While this feature is universal in transition metal pnictides, in TlNi$_2$Se$_2$ it lies in the immediate vicinity of the Fermi level, giving rise to a pronounced van Hove singularity. The resulting heavy band mass resolves the apparent puzzle of a large normal-state specific heat coefficient (Phys. Rev. Lett. 112, 207001) in this weakly correlated compound.
%U http://arxiv.org/abs/1412.7016v1