Microscopic properties of the "pinwheel" kagome compound Rb_2Cu_3SnF_{12}

Abstract

Using ${}^{63,65}$Cu nuclear magnetic resonance (NMR) in magnetic fields up to 30 T we study the microscopic properties of the 12-site valence-bond-solid ground state in the "pinwheel" kagome compound Rb${}_2$Cu${}_3$SnF${}_{12}$. We find that the ground state is characterized by a strong transverse staggered spin polarization whose temperature and field dependence points to a mixing of the singlet and triplet states. This is further corroborated by the field dependence of the gap $\Delta (H)$, which has a level anticrossing with a large minimum gap value of $\approx \Delta (0)/2$, with no evidence of a phase transition down to 1.5\,K. By the exact diagonalization of small clusters, we show that the observed anticrossing is mainly due to staggered tilts of the $g$-tensors defined by the crystal structure, and reveal symmetry properties of the low-energy excitation spectrum compatible with the absence of level crossing.

version 2: 5 pages, 4 figures + in Supplementary material: 3 pages, 2 figures. Accepted for publication in Physical Review Letters

References in corpus (5)

• Pinwheel VBS state and triplet excitations in the two-dimensional deformed kagome lattice
• Singlet Ground State and Spin Gap in S=1/2 Kagome Antiferromagnet Rb${}_2$Cu${}_3$SnF${}_{12}$
• Spin Configuration in the 1/3 Magnetization Plateau of Azurite Determined by NMR
• p6 - Chiral Resonating Valence Bonds in the Kagome Antiferromagnet
• Influence of Dzyaloshinskii-Moriya interactions on magnetic structure of a spin-1/2 deformed kagome lattice antiferromagnet

Cited by in corpus (5)

• From spin liquid to magnetic ordering in the anisotropic kagome Y-Kapellasite Y3Cu9(OH)19Cl8: a single crystal study
• Magnetic structure and high-field magnetization of the distorted kagome lattice antiferromagnet Cs${}_2$Cu${}_3$SnF${}_{12}$
• ${\mathbb{Z}}_2$ gauge theory for valence bond solids on the kagome lattice
• Controlling frustrated magnetism on the kagome lattice by uniaxial-strain tuning
• Ghost modes and continuum scattering in the dimerized distorted kagome lattice antiferromagnet Rb${}_2$Cu${}_3$SnF${}_{12}$