Anisotropy-induced soliton excitation in magnetized strong-rung spin ladders

Abstract

We report low temperature electron spin resonance experimental and theoretical studies of an archetype $S=1/2$ strong-rung spin ladder material (C${}_5$H${}_{12}$N)${}_2$CuBr${}_4$. 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 $g$-factor values. Field theoretical analysis demonstrates that the observed low-energy excitation modes in magnetized (C${}_5$H${}_{12}$N)${}_2$CuBr${}_4$ are solitonic excitations caused by Dzyaloshinskii-Moriya interaction presence.

6 pages main text and 4 figures with supplemental materials 8 pages and 2 figures

References in corpus (7)

• Thermodynamics of the Spin Luttinger-Liquid in a Model Ladder Material
• Direct Observation of Magnon Fractionalization in the Quantum Spin Ladder
• Field-Controlled Magnetic Order in the Quantum Spin-Ladder System (Hpip)2CuBr4
• Spin-resonance modes of the spin-gap magnet TlCuCl_3
• Anisotropy of Magnetic Interactions in the Spin-Ladder Compound (C${}_5$H${}_{12}$N)${}_2$CuBr${}_4$
• Scaling of temporal correlations in an attractive Tomonaga-Luttinger spin liquid
• Dynamical Correlations of the Spin-1/2 Heisenberg XXZ Chain in a Staggered Field