Emergent tetragonality in a fundamentally orthorhombic material

Journal article

Symmetry plays a key role in determining the physical properties of materials. By Neumann's principle, the properties of a material remain invariant under the symmetry operations of the space group to which the material belongs. Continuous phase transitions are associated with a spontaneous reduction in symmetry. Less common are examples where proximity to a continuous phase transition leads to an increase in symmetry. We find signatures of an emergent tetragonal symmetry close to a charge density wave (CDW) bicritical point in a fundamentally orthorhombic material, ErTe3, for which the two distinct CDW phase transitions are tuned via anisotropic strain. We first establish that tension along the a axis favors an abrupt rotation of the CDW wave vector from the c to a axis and infer the presence of a bicritical point where the two continuous phase transitions meet. We then observe a divergence of the nematic elastoresistivity approaching this putative bicritical point, indicating an emergent tetragonality in the critical behavior.

Authors: Singh, AG; Bachmann, MD; Sanchez, JJ; Pandey, A; Kapitulnik, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Association for the Advancement of Science
• Journal: Science Advances
• Volume: 10
• Issue: 21
• Pages: eadk3321
• Publication date: 2024-05-23
• DOI: 10.1126/sciadv.adk3321
• EISSN: 2375-2548
• ISSN: 2375-2548
• Pmid: 38781340
• Language: English
• Keywords: Orthorhombic crystal system; Materials science; Chemistry; Crystallography; Crystal structure