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arXiv · 2011.12951

Evidence for freezing of charge degrees of freedom across a critical point in CeCoIn$_5$

Nikola Maksimovic·Tessa Cookmeyer·Jan Rusz·Vikram Nagarajan·Amanda Gong·Fanghui Wan·Stefano Faubel·Ian M. Hayes·Sooyoung Jang·Yochai Werman·Peter M. Oppeneer·Ehud Altman·James G. Analytis
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Abstract

The presence of a quantum critical point separating two distinct zero-temperature phases is thought to underlie the `strange' metal state of many high-temperature superconductors. The nature of this quantum critical point, as well as a description of the resulting strange metal, are central open problems in condensed matter physics. In large part, the controversy stems from the lack of a clear broken symmetry to characterize the critical phase transition, and this challenge is no clearer than in the example of the unconventional superconductor CeCoIn$_5$. Through Hall effect and Fermi surface measurements of CeCoIn$_5$, in comparison to ab initio calculations, we find evidence for a critical point that connects two Fermi surfaces with different volumes without apparent symmetry-breaking, indicating the presence of a transition that involves an abrupt localization of one sector of the charge degrees of freedom. We present a model for the anomalous electrical Hall resistivity of this material based on the conductivity of valence charge fluctuations.

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Nikola Maksimovic, Tessa Cookmeyer, Jan Rusz, Vikram Nagarajan, Amanda Gong, Fanghui Wan, Stefano Faubel, Ian M. Hayes, Sooyoung Jang, Yochai Werman, Peter M. Oppeneer, Ehud Altman, James G. Analytis. 2020-11-25. Evidence for freezing of charge degrees of freedom across a critical point in CeCoIn$_5$. https://arxiv.org/abs/2011.12951

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