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arXiv · 2412.09047

Rotational Gr\"{u}neisen ratio: a probe for quantum criticality in anisotropic systems

Shohei Yuasa·Yohei Kono·Yuta Ozaki·Minoru Yamashita·Yasuyuki Shimura·Toshiro Takabatake·Shunichiro Kittaka
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Abstract

The Gr\"{u}neisen ratio $\Gamma$ and its magnetic analog, the magnetic Gr\"{u}neisen ratio $\Gamma_H$, are powerful probes to study the nature of quantum phase transitions. Here, we propose a Gr\"{u}neisen parameter, the rotational Gr\"{u}neisen ratio $\Gamma_\phi$, by introducing the orientation of the external field as a control parameter. We investigate $\Gamma_\phi$ of the highly anisotropic paramagnets CeRhSn and CeIrSn by measuring the rotational magnetocaloric effect in a wide range of temperatures and magnetic fields. We find that the $\Gamma_\phi$ data of both compounds are scaled by using the same critical exponents and the field-invariant critical field angle. Remarkably, the scaling function for the $\Gamma_\phi$ data reveals the presence of highly anisotropic quantum criticality that develops as a function of the easy-axis component of the magnetic field from the quantum critical line. This paper provides a thermodynamic approach to detect and identify magnetic quantum criticality in highly anisotropic systems.

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Shohei Yuasa, Yohei Kono, Yuta Ozaki, Minoru Yamashita, Yasuyuki Shimura, Toshiro Takabatake, Shunichiro Kittaka. 2024-12-12. Rotational Gr\"{u}neisen ratio: a probe for quantum criticality in anisotropic systems. https://doi.org/10.1103/physrevb.111.045123

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