High-field spectroscopy of singlet-triplet transitions in the spin-dimer systems Sr3Cr2O8 and Ba3Cr2O8

Zhe Wang (1) , D. Kamenskyi , Olivier Cepas (2) , M. Schmidt , D. L. Quintero-Castro , A. T. M. N. Islam , B. Lake (3) , A. A. Aczel , H. A. Dabkowska , A. B. Dabkowski , G. M. Luke , Yuan Wan , A. Loidl (1) , M. Ozerov , J. Wosnitza (4) , S. A. Zvyagin , J. Deisenhofer

1 Experimentalphysik V, Center for Electronic Correlations and Magnetism, Institute for Physics
2 NEEL - TMC - Théorie de la Matière Condensée
3 HZB - Helmholtz-Zentrum Berlin für Materialien und Energie GmbH = Helmholtz Centre Berlin for Materials and Energy = Centre Helmholtz de Berlin pour les matériaux et l'énergie
4 Dresden High Magnetic Field Laboratory

Magnetic excitations in the isostructural spin-dimer systems Sr3Cr2O8 and Ba3Cr2O8 are probed by means of high-field electron spin resonance at sub-terahertz frequencies. Three types of magnetic modes were observed. One mode is gapless and corresponds to transitions within excited states, while two other sets of modes are gapped and correspond to transitions from the ground to the first excited states. The selection rules of the gapped modes are analyzed in terms of a dynamical Dzyaloshinskii-Moriya interaction, suggesting the presence of phonon-assisted effects in the low-temperature spin dynamics of Sr3Cr2O8 and Ba3Cr2O8

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Zhe Wang, D. Kamenskyi, Olivier Cepas, M. Schmidt, D. L. Quintero-Castro, et al.. High-field spectroscopy of singlet-triplet transitions in the spin-dimer systems Sr3Cr2O8 and Ba3Cr2O8. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2014, 89 (17), pp.1774406. ⟨10.1103/PhysRevB.89.174406⟩. ⟨hal-00989668⟩