Anisotropic Spin Stripe Domains in Bilayer La3Ni2O7
Feb 7, 2025
2:30PM to 3:30PM
Date/Time
Date(s) - 07/02/2025
2:30 pm - 3:30 pm
Categories
Prof. David Hawthorn
Department of Physics and Astronomy, University of Waterloo
Abstract: Recently a new high temperature superconductor, La3Ni2O7, has been discovered with Tc = 80 K under high pressure. In other high temperature superconductors, such as the cuprates or pnictides, superconductivity emerges from the suppression of a parent magnetically ordered state. This has motivated the investigation of a parent spin density wave (SDW) state La3Ni2O7. In this talk, I will describe how we use resonant soft x-ray scattering and polarimetry measurements at ambient pressures to detect and characterize SDW order in thin films of bilayer La3Ni2O7. We show that the SDW order forms unidirectional diagonal spin stripes with moments lying within the NiO2 plane and perpendicular to propagation direction of the SDW. These spin stripes form anisotropic domains, revealing nanoscale rotational and translational symmetry breaking analogous to the cuprate and Fe-based superconductors, with Bloch-like antiferromagnetic domain walls separating orthogonal domains. I will discuss measurements looking for, but not detecting, evidence of charge order in La3Ni2O7.
Reference: N. K Gupta, R. Gong, Y. Wu, M. Kang, C. T. Parzyck, B. Z. Gregory, N. Costa, R. Sutarto, S. Sarker, A. Singer, D. G. Schlom, K. M. Shen and D. G. Hawthorn. arXiv: 2409.03210 (2024).
Biography: Professor Hawthorn is a Professor in the Department of Physics and Astronomy at the University of Waterloo. His research is primarily focused on studies of Quantum Materials, such as high temperature superconductors, using advanced synchrotron-based x-ray techniques – resonant soft x-ray scattering and x-ray absorption spectroscopy.
In-Person: ABB 102
Online: https://mcmaster.zoom.us/j/91326225023
Meeting ID: 913 2622 5023
Passcode: 530483