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arXiv · 2411.11164

Conformally invariant charge fluctuations in a strange metal

Xuefei Guo·Jin Chen·Farzaneh Hoveyda-Marashi·Simon L. Bettler·Dipanjan Chaudhuri·Caitlin S. Kengle·John A. Schneeloch·Ruidan Zhang·Genda Gu·Tai-Chang Chiang·Alexei M. Tsvelik·Thomas Faulkner·Philip W. Phillips·Peter Abbamonte
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Abstract

The strange metal is a peculiar phase of matter in which the electron scattering rate, $\tau^{-1} \sim k_B T/\hbar$, which determines the electrical resistance, is universal across a wide family of materials and determined only by fundamental constants. In 1989, theorists hypothesized that this universality would manifest as scale-invariant behavior in the dynamic charge susceptibility, $\chi''(q,\omega)$. Here, we present momentum-resolved inelastic electron scattering measurements of the strange metal Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ showing that the susceptibility has the scale-invariant form $\chi''(q,\omega) = T^{-\nu} f(\omega/T)$, with exponent $\nu = 0.93$. We find the response is consistent with conformal invariance, meaning the dynamics may be thought of as occurring on a circle of radius $1/T$ in imaginary time, characterized by conformal dimension $\Delta = 0.05$. Our study indicates that the strange metal is a universal phenomenon whose properties are not determined by microscopic properties of a particular material.

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Xuefei Guo, Jin Chen, Farzaneh Hoveyda-Marashi, Simon L. Bettler, Dipanjan Chaudhuri, Caitlin S. Kengle, John A. Schneeloch, Ruidan Zhang, Genda Gu, Tai-Chang Chiang, Alexei M. Tsvelik, Thomas Faulkner, Philip W. Phillips, Peter Abbamonte. 2024-11-17. Conformally invariant charge fluctuations in a strange metal. https://arxiv.org/abs/2411.11164

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