Random singlet physics in the S = (1)/(2) pyrochlore antiferromagnet NaCdCu₂F₇

2025/09/24 by Kancko, Andrej, Sakai, Hironori, Corrêa, Cinthia Antunes +7
#FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el)

paper · doi:10.48550/arxiv.2509.20199

Abstract

We report a random singlet ground state in the S = (1)/(2) Heisenberg pyrochlore antiferromagnet NaCdCu₂F₇. Cationic Na⁺/Cd²⁺ disorder generates a broad distribution of Cu²⁺-F^--Cu²⁺ exchange couplings. Despite strong antiferromagnetic interactions, no magnetic order or freezing occurs, with μSR measurements confirming dynamics down to 58 mK. T-linear specific heat, a Curie-like susceptibility tail, and universal power-law scaling with data collapse in χ(T), M(H), C_{\rm mag}/T, ²³Na (1/T₁T) and λ_{\rm LF} demonstrate a disorder-driven network of singlets and orphan spins, distinct from a clean quantum spin liquid.

Citations

• Can experimentally-accessible measures of entanglement distinguish quantum spin liquids from disorder-driven "random singlet" phases ?
• VESTA: a three-dimensional visualization system for electronic and structural analysis
• SUPERFLIP– a computer program for the solution of crystal structures by charge flipping in arbitrary dimensions
• Non-Abelian anyons and topological quantum computation
• Quantum spin liquids
• Fault-tolerant quantum computation by anyons

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