Sixfold Enhancement of Superconductivity in a Tunable Electronic Nematic System

Published

March 1, 2020

Author(s)

Christoper Eckberg, Daniel J. Campbell, Tristin Metz, John Collini, Halyna Hodovanets, Tyler Drye, Peter Zavalij, Morten H. Christensen, Rafael M. Fernandes, Sangjun Lee, Peter Abbamonte, Jeffrey W. Lynn, Johnpierre Paglione

Abstract

The electronic nematic phase, wherein electronic degrees of freedom lower the crystal rotational symmetry, is a common motif across a number of high-temperature superconductors. However, understanding the role and influence of nematicity and nematic fluctuations in Cooper pairing is often complicated by the coexistence of other orders, particularly long-range magnetic order. Here we report the enhancement of superconductivity in a model electronic nematic system absent of magnetism, and show that the enhancement is directly born out of strong nematic fluctuations emanating from a tuned quantum phase transition. We use elastoresistance measurements of the Ba_1-xSr_xNi₂As₂ substitution series to show that strontium substitution promotes an electronically driven B_1g nematic order in this system, and that the complete suppression of that order to absolute zero temperature evokes a dramatic enhancement of the pairing strength, as evidenced by a sixfold increase in the superconducting transition temperature. The direct relation between enhanced pairing and nematic fluctuations in this model system, as well as the interplay with a unidirectional charge density wave order comparable to that found in the cuprates, offers a means to elucidate the role of nematicity in boosting superconductivity.

Citation

Nature Physics

Volume

16

Issue

3

Pub Type

Journals

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Keywords

Iron superconductors, electronic nematic phase, sixfold Tc increase, resistivity data, neutron diffraction

Citation

Eckberg, C. , Campbell, D. , Metz, T. , Collini, J. , Hodovanets, H. , Drye, T. , Zavalij, P. , Christensen, M. , Fernandes, R. , Lee, S. , Abbamonte, P. , Lynn, J. and Paglione, J. (2020), Sixfold Enhancement of Superconductivity in a Tunable Electronic Nematic System, Nature Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=927727 (Accessed October 20, 2025)