Precise band-filling control is performed on a strongly correlated electron system NaxCoO2, by changing the Na content, and the influence of this on the magnetic and thermodynamic properties is studied. It has been discovered that a phase boundary between a Pauli paramagnetic metal appearing at small x and a Curie-Weiss metal at large x is located within an extremely narrow range of 0.620 < x < 0.621. The transition between these is a Lifshitz transition of the pocket-vanishing type, exceptionally achieved by band-filling control. Abrupt changes in various properties across the boundary are remarkably observed, suggesting that the Lifshitz transition occurs discontinuously in NaxCoO2, differently from the conventional Lifshitz transition defined at T = 0.
@article{arxiv.1002.4282,
title = {Discontinuous Lifshitz Transition Achieved by Band-Filling Control in NaxCoO2},
author = {Yoshihiko Okamoto and Atsushi Nishio and Zenji Hiroi},
journal= {arXiv preprint arXiv:1002.4282},
year = {2015}
}
Comments
5 pages, 5 figures, to be published in Phys. Rev. B