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TT: Fachverband Tiefe Temperaturen
TT 45: Correlated Electrons: 1D Theory
TT 45.2: Talk
Thursday, March 30, 2023, 09:45–10:00, HSZ 103
Electron spin resonance as a direct probe of spinon interactions in a S=1/2 chain — •Kirill Povarov1,2, Timofei Soldatov3, Ren-Bo Wang4, Andrey Zheludev1, Alexander Smirnov3, and Oleg Starykh4 — 1Laboratory for Solid State Physics, ETH Zürich — 2Dresden High Magnetic Field Laboratory (HLD), Helmholtz-Zentrum Dresden-Rossendorf (HZDR) — 3P.L. Kaptiza Institute for Physical Problems RAS — 4Department of Physics and Astronomy, University of Utah
The presence of well-hidden backscattering between the fractionalized spinon excitations was known to be a somewhat exotic part of the S=1/2 chain physics. However, its dramatic consequences for the dynamics were realized recently [1]. They are challenging for observation, as applied field and nonzero momenta are simultaneously required. We have succeeded in the experimental verification of these effects using electron spin resonance as probe [2]. Our observations are enabled by the specific pattern of Dzyaloshinskii–Moriya interactions in our target material K2CuSO4Br2. Description of the observed spectrum requires accounting for the backscattering on a qualitative level. Quantitative analysis allows us to estimate the backscattering constant as 2.4J (intrachain exchange), in agreement with the renormalization group predictions.
This work has been supported by SNSF Division II (ETHZ), the NSF CMMT grant DMR-1928919 (U. Utah), and the RSF Grant 17-12-01505 (IPP).
[1] A. Keselman et al., PRL 125, 187201 (2020)
[2] K. Povarov et al., PRL 128, 187202 (2022) Editor’s Suggestion