Strain and vector magnetic field tuning of the anomalous phase in Sr₃Ru₂O₇

• Autores: Brodsky, Daniel O.; Barber, Mark E.; Bruin, Jan A. N.; Borzi, Rodolfo Alberto; Grigera, Santiago Andrés; Perry, Robin S.; Mackenzie, Andrew P.; Hicks, Clifford W.
• Año de publicación: 2017
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Ciencias Exactas; superconductivity
• Institución: Universidad Nacional de La Plata

A major area of interest in condensed matter physics is the way electrons in correlated electron materials can self-organize into ordered states, and a particularly intriguing possibility is that they spontaneously choose a preferred direction of conduction. The correlated electron metal Sr₃Ru₂O₇ has an anomalous phase at low temperatures that features strong susceptibility toward anisotropic transport. This susceptibility has been thought to indicate a spontaneous anisotropy, that is, electronic order that spontaneously breaks the point-group symmetry of the lattice, allowing weak external stimuli to select the orientation of the anisotropy. We investigate further by studying the response of Sr₃Ru₂O₇ in the region of phase formation to two fields that lift the native tetragonal symmetry of the lattice: in-plane magnetic field and orthorhombic lattice distortion through uniaxial pressure. The response to uniaxial pressure is surprisingly strong: Compressing the lattice by ~0.1% induces an approximately 100% transport anisotropy. However, neither the in-plane field nor the pressure phase diagrams are qualitatively consistent with spontaneous symmetry reduction. Instead, both are consistent with a multicomponent order parameter that is likely to preserve the point-group symmetry of the lattice, but is highly susceptible to perturbation.
Instituto de Física de Líquidos y Sistemas Biológicos
Facultad de Ciencias Exactas