Understanding the organizing principles of interacting electrons and the emergence of novel electronic phases is a central endeavor of condensed matter physics. Electronic nematicity, in which the discrete rotational symmetry in the electron fluid is broken while the translational one remains unaffected, is a prominent example of such a phase. It has proven ubiquitous in correlated electron systems, and is of prime importance to understand Fe-based superconductors. Here, we find that fluctuations of such broken symmetry are exceptionally strong over an extended temperature range above phase transitions in \bnap, the nickel homologue to the Fe-based systems. This provides evidence for a type of electronic nematicity, dynamical in nature, which exhibits an unprecedented coupling to the underlying crystal lattice. Fluctuations between degenerate nematic configurations cause a splitting of phonon lines, without lifting degeneracies nor breaking symmetries, akin to spin liquids in magnetic systems.
@article{arxiv.2207.03161,
title = {An Electronic Nematic Liquid in BaNi$_2$As$_2$},
author = {Yi Yao and Roland Willa and Tom Lacmann and Sofia-Michaela Souliou and Mehdi Frachet and Kristin Willa and Michael Merz and Frank Weber and Christoph Meingast and Rolf Heid and Amir-Abbas Haghighirad and Jörg Schmalian and Matthieu Le Tacon},
journal= {arXiv preprint arXiv:2207.03161},
year = {2022}
}
Comments
Originally submitted version (references have been updated). The version to be published has been significantly revised and is available upon request to MLT