The electronic nematic phase of Sr3Ru2O7 is investigated by high-resolution in-plane thermal expansion measurements in magnetic fields close to 8 T applied at various angles Θ off the c-axis. At Θ<10∘ we observe a very small (10−7) lattice distortion which breaks the four-fold in-plane symmetry, resulting in nematic domains with interchanged a- and b-axis. At Θ≳10∘ the domains are almost fully aligned and thermal expansion indicates an area-preserving lattice distortion of order 2×10−6 which is likely related to orbital ordering. Since the system is located in the immediate vicinity to a metamagnetic quantum critical end point, the results represent the first observation of a structural relaxation driven by quantum criticality.
@article{arxiv.1012.4672,
title = {Symmetry-breaking lattice distortion in Sr_3Ru_2O_7},
author = {C. Stingl and R. S. Perry and Y. Maeno and P. Gegenwart},
journal= {arXiv preprint arXiv:1012.4672},
year = {2011}
}