Sleuthing out exotic quantum spin liquidity in the pyrochlore magnet Ce2Zr2O7

• Published in: npj quantum materials Vol. 7; no. 1; pp. 1 - 8
• Main Authors: Bhardwaj, Anish, Zhang, Shu, Yan, Han, Moessner, Roderich, Nevidomskyy, Andriy H., Changlani, Hitesh J.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 02.05.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/119/999; 639/766/119/997; Condensed Matter Physics; Experiments; Heat; Magnets; Physics; Physics and Astronomy; Pyrochlores; Quantum Physics; Spin dynamics; Spin liquid; Structural Materials; Surfaces and Interfaces; Thin Films
• ISSN: 2397-4648; 2397-4648
• DOI: 10.1038/s41535-022-00458-2

The search for quantum spin liquids—topological magnets with fractionalized excitations—has been a central theme in condensed matter and materials physics. Despite numerous theoretical proposals, connecting experiment with detailed theory exhibiting a robust quantum spin liquid has remained a central challenge. Here, focusing on the strongly spin-orbit coupled effective S  = 1/2 pyrochlore magnet Ce 2 Zr 2 O 7 , we analyze recent thermodynamic and neutron-scattering experiments, to identify a microscopic effective Hamiltonian through a combination of finite temperature Lanczos, Monte Carlo, and analytical spin dynamics calculations. Its parameter values suggest the existence of an exotic phase, a π -flux U(1) quantum spin liquid. Intriguingly, the octupolar nature of the moments makes them less prone to be affected by magnetic disorder, while also hiding some otherwise characteristic signatures from neutrons, making this spin liquid arguably more stable than its more conventional counterparts.