Abstract
Fractionalized excitations such as spinons and anyons have emerged as a central theme in condensed matter physics with broad implications for superconductivity, quantum statistics, and quantum computation. The nearly ideal one-dimensional S = 1/2 system β-VOSO4 without long-range order down to 85 mK provides a promising platform to experimentally explore such fractionalized excitations. Here, we employ Raman spectroscopy to probe magnetic excitations and the evolution of spin correlations in β-VOSO4. Spinon signatures are found along the chain direction, evidenced by a broad, gapless scattering continuum at low temperatures. The temperature dependence of the spinon spectral weight aligns considerably with numerical density matrix renormalization group calculations. By comparing the experimental spinon spectral weight with calculated results and evaluating the associated quantum Fisher information (QFI) therefrom, we observe a steep increase in QFI upon cooling, indicating rapidly growing correlation lengths. Our study showcases QFI as a probe of spin correlations in quantum magnets. (Figure presented.)
| Original language | English |
|---|---|
| Article number | 447 |
| Journal | Communications Physics |
| Volume | 8 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 2025 |
Funding
The work of P.L. and E.D. was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), Materials Sciences and Engineering Division. G.A. contributed to the DMRG work, and was supported by the U.S. DOE, Office of Science, National Quantum Information Science Research Centers, Quantum Science Center. D.W. was supported by the faculty research fund of Sejong University in 2025, and by the Institute of Applied Physics of Seoul National University. K.Y.C. acknowledges support from the Nano-Material Technology Development Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Science and ICT (RS-2023-00281839).