skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Micron-scale measurements of low anisotropic strain response of local $$T_c$$ in Sr$$_2$$RuO$$_4$$

Abstract

Strontium ruthenate (Sr$$_2$$RuO$$_4$$) is a multiband superconductor that displays evidence of topological superconductivity, although a model of the order parameter that is consistent with all experiments remains elusive. We integrated a piezoelectric-based strain apparatus with a scanning superconducting quantum interference device (SQUID) microscope to map the diamagnetic response of single-crystal Sr$$_2$$RuO$$_4$$ as a function of temperature, uniaxial pressure, and position with micron-scale spatial resolution. We thereby obtained local measurements of the superconducting transition temperature $$T_c$$ vs. anisotropic strain $$\epsilon$$ with sufficient sensitivity for comparison to theoretical models that assume a uniform $$p_x\pm ip_y$$ order parameter. We found that $$T_c$$ varies with position and that the locally measured $$T_c$$ vs. $$\epsilon$$ curves are quadratic ($$T_c\propto\epsilon^2$$), as allowed by the C$$_4$$ symmetry of the crystal lattice. We did not observe the low-strain linear cusp ($$T_c\propto \left| \epsilon \right|$$) that would be expected for a two-component order parameter such as $$p_x\pm ip_y$$. Lastly, these results provide new input for models of the order parameter of Sr$$_2$$RuO$$_4$$.

Authors:
 [1];  [2];  [3];  [4];  [5]
  1. SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Institute for Materials and Energy Science (SIMES)
  2. SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Institute for Materials and Energy Sciences
  3. Univ. of St. Andrews, St. Andrews (United Kingdom). Scottish Univ. Physics Alliance, School of Physics and Astronomy; STFC Rutherford Appleton Lab., Didcot (United Kingdom)
  4. Univ. of St. Andrews, St. Andrews (United Kingdom). Scottish Univ. Physics Alliance, School of Physics and Astronomy; Max Planck Institute for Chemical Physics of Solids, Dresden (Germany)
  5. Max Planck Institute for Chemical Physics of Solids, Dresden (Germany)
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; USDOE
OSTI Identifier:
1466112
Alternate Identifier(s):
OSTI ID: 1474003
Report Number(s):
APS/123-QED
Journal ID: ISSN 2469-9950
Grant/Contract Number:  
AC02-76SF00515
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 98; Journal Issue: 9; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Condensed matter physics; Superconductivity; Materials science

Citation Formats

Moler, Kathryn Ann, Watson, Christopher A., Gibbs, Alexander S., Mackenzie, Andrew P., and Hicks, Clifford W. Micron-scale measurements of low anisotropic strain response of local $T_c$ in Sr$_2$RuO$_4$. United States: N. p., 2018. Web. doi:10.1103/PhysRevB.98.094521.
Moler, Kathryn Ann, Watson, Christopher A., Gibbs, Alexander S., Mackenzie, Andrew P., & Hicks, Clifford W. Micron-scale measurements of low anisotropic strain response of local $T_c$ in Sr$_2$RuO$_4$. United States. doi:10.1103/PhysRevB.98.094521.
Moler, Kathryn Ann, Watson, Christopher A., Gibbs, Alexander S., Mackenzie, Andrew P., and Hicks, Clifford W. Wed . "Micron-scale measurements of low anisotropic strain response of local $T_c$ in Sr$_2$RuO$_4$". United States. doi:10.1103/PhysRevB.98.094521. https://www.osti.gov/servlets/purl/1466112.
@article{osti_1466112,
title = {Micron-scale measurements of low anisotropic strain response of local $T_c$ in Sr$_2$RuO$_4$},
author = {Moler, Kathryn Ann and Watson, Christopher A. and Gibbs, Alexander S. and Mackenzie, Andrew P. and Hicks, Clifford W.},
abstractNote = {Strontium ruthenate (Sr$_2$RuO$_4$) is a multiband superconductor that displays evidence of topological superconductivity, although a model of the order parameter that is consistent with all experiments remains elusive. We integrated a piezoelectric-based strain apparatus with a scanning superconducting quantum interference device (SQUID) microscope to map the diamagnetic response of single-crystal Sr$_2$RuO$_4$ as a function of temperature, uniaxial pressure, and position with micron-scale spatial resolution. We thereby obtained local measurements of the superconducting transition temperature $T_c$ vs. anisotropic strain $\epsilon$ with sufficient sensitivity for comparison to theoretical models that assume a uniform $p_x\pm ip_y$ order parameter. We found that $T_c$ varies with position and that the locally measured $T_c$ vs. $\epsilon$ curves are quadratic ($T_c\propto\epsilon^2$), as allowed by the C$_4$ symmetry of the crystal lattice. We did not observe the low-strain linear cusp ($T_c\propto \left| \epsilon \right|$) that would be expected for a two-component order parameter such as $p_x\pm ip_y$. Lastly, these results provide new input for models of the order parameter of Sr$_2$RuO$_4$.},
doi = {10.1103/PhysRevB.98.094521},
journal = {Physical Review B},
number = 9,
volume = 98,
place = {United States},
year = {2018},
month = {9}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 5 works
Citation information provided by
Web of Science

Save / Share: