Uniaxial Strain Tuning of Superconductivity in 2$H$-NbSe$_{2}$

Andrew Wieteska; Ben Foutty; Zurab Guguchia; Felix Flicker; Ben Mazel; Lyuwen Fu; Shuang Jia; Chris Marianetti; Jasper van Wezel; Abhay Pasupathy

arXiv · 1903.05253

Uniaxial Strain Tuning of Superconductivity in 2$H$-NbSe$_{2}$

Andrew Wieteska·Ben Foutty·Zurab Guguchia·Felix Flicker·Ben Mazel·Lyuwen Fu·Shuang Jia·Chris Marianetti·Jasper van Wezel·Abhay Pasupathy

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Abstract

We explore the effect of lattice anisotropy on the charge-ordered superconductor 2H-NbSe$_{2}$. Using a novel strain apparatus, we measure the superconducting transition temperature $T_{sc}$ as a function of uniaxial strain. It is found that $T_{sc}$ is independent of tensile(compressive) strain below a threshold of 0.2\% (0.1\%), but decreases strongly with larger strains with an average rate of $1.3\,$K/\% ($2.5\,$K/\%). Transport signatures of charge order are largely unaffected as a function of strain. Theoretical considerations show that the change in the behavior of $T_{sc}$ with strain coincides with a phase transition from 3Q to 1Q charge order in the material. The spectral weight on one of the Fermi surface bands is found to change strongly as a consequence of this phase transition, providing a pathway to tune superconducting order.

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Andrew Wieteska, Ben Foutty, Zurab Guguchia, Felix Flicker, Ben Mazel, Lyuwen Fu, Shuang Jia, Chris Marianetti, Jasper van Wezel, Abhay Pasupathy. 2019-03-12. Uniaxial Strain Tuning of Superconductivity in 2$H$-NbSe$_{2}$. https://arxiv.org/abs/1903.05253

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