Abstract
We report low temperature electron spin resonance experimental and theoretical studies of an archetype strong-rung spin ladder material . Unexpected dynamics is detected deep in the Tomonaga-Luttinger spin liquid regime. Close to the point where the system is half-magnetized (and believed to be equivalent to a gapless easy plane chain in zero field) we observed orientation-dependent spin gap and anomalous -factor values. Field theoretical analysis demonstrates that the observed low-energy excitation modes in magnetized are solitonic excitations caused by Dzyaloshinskii-Moriya interaction presence.
- Received 5 February 2020
- Revised 5 June 2020
- Accepted 23 June 2020
DOI:https://doi.org/10.1103/PhysRevLett.125.027204
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