Symmetry-breaking lattice distortion in Sr_3Ru_2O_7

Abstract

The electronic nematic phase of Sr${}_3$Ru${}_2$O${}_7$ is investigated by high-resolution in-plane thermal expansion measurements in magnetic fields close to 8 T applied at various angles $\Theta$ off the c-axis. At $\Theta <10^{\circ }$ 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 $\Theta \gtrsim 10^{\circ }$ the domains are almost fully aligned and thermal expansion indicates an area-preserving lattice distortion of order $2\times 10^{-6}$ 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.

4 pages, 5 figures, PRL accepted

References in corpus (4)

• Evidence for an electron nematic phase transition in underdoped iron pnictide superconductors
• Formation of a Nematic Fluid at High Fields in Sr3Ru2O7
• Metamagnetic quantum criticality in Sr3Ru2O7 studied by thermal expansion
• Unconventional metamagnetic electron states in orbital band systems