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arXiv · 2009.11280

Specific Heat of a Quantum Critical Metal

Ori Grossman·Johannes S. Hofmann·Tobias Holder·Erez Berg
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Abstract

We investigate the specific heat, $c$, near an Ising nematic quantum critical point (QCP), using sign problem-free quantum Monte Carlo simulations. Cooling towards the QCP, we find a broad regime of temperature where $c/T$ is close to the value expected from the non-interacting band structure, even for a moderately large coupling strength. At lower temperature, we observe a rapid rise of $c/T$, followed by a drop to zero as the system becomes superconducting. The spin susceptibility begins to drop at roughly the same temperature where the enhancement of $c/T$ onsets, most likely due to the opening of a gap associated with superconducting fluctuations. These findings suggest that superconductivity and non-Fermi liquid behavior (manifested in an enhancement of the effective mass) onset at comparable energy scales. We support these conclusions with an analytical perturbative calculation.

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Ori Grossman, Johannes S. Hofmann, Tobias Holder, Erez Berg. 2020-09-23. Specific Heat of a Quantum Critical Metal. https://doi.org/10.1103/physrevlett.127.017601

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