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arXiv · 1709.06545

Resistivity in the Vicinity of a Van Hove Singularity: Sr$_2$RuO$_4$ Under Uniaxial Pressure

Mark E. Barber·Alexandra S. Gibbs·Yoshiteru Maeno·Andrew P. Mackenzie·Clifford W. Hicks
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Abstract

We report the results of a combined study of the normal state resistivity and superconducting transition temperature $T_c$ of the unconventional superconductor Sr$_2$RuO$_4$ under uniaxial pressure. There is strong evidence that as well as driving $T_c$ through a maximum at $\sim$3.5 K, compressive strains $\varepsilon$ of nearly 1 % along the crystallographic [100] axis drive the $\gamma$ Fermi surface sheet through a Van Hove singularity, changing the temperature dependence of the resistivity from $T^2$ above and below the transition region to $T^{1.5}$ within it. This occurs in extremely pure single crystals in which the impurity contribution to the resistivity is $<$100 n$\Omega$cm, so our study also highlights the potential of uniaxial pressure as a more general probe of this class of physics in clean systems.

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Mark E. Barber, Alexandra S. Gibbs, Yoshiteru Maeno, Andrew P. Mackenzie, Clifford W. Hicks. 2017-09-19. Resistivity in the Vicinity of a Van Hove Singularity: Sr$_2$RuO$_4$ Under Uniaxial Pressure. https://doi.org/10.1103/physrevlett.120.076602

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