We report angle-resolved photoelectron spectroscopy measurements of the quantum critical metal Sr3Ru2O7 revealing itinerant Ru 4d-states confined over large parts of the Brillouin zone to an energy range of < 6 meV, nearly three orders of magnitude lower than the bare band width. We show that this energy scale agrees quantitatively with a characteristic thermodynamic energy scale associated with quantum criticality and illustrate how it arises from the hybridization of light and strongly renormalized, heavy quasiparticle bands. For the largest Fermi surface sheet we find a marked k-dependence of the renormalization and show that it correlates with the Ru 4d - O 2p hybridization.
@article{arxiv.1210.8382,
title = {Formation and consequences of heavy d-electron quasiparticles in Sr3Ru2O7},
author = {M. P. Allan and A. Tamai and E. Rozbicki and M. H. Fischer and J. Voss and P. D. C. King and W. Meevasana and S. Thirupathaiah and E. Rienks and J. Fink and A. Tennant and R. S. Perry and J. F. Mercure and M. A. Wang and C. J. Fennie and E. -A. Kim and M. J. Lawler and K. M. Shen and A. P. Mackenzie and Z. -X. Shen and F. Baumberger},
journal= {arXiv preprint arXiv:1210.8382},
year = {2013}
}