Fizika Nizkikh Temperatur: Volume 47, Number 11 (November 2021), p. 1011-1021 ( to contents , go back )
Magnetic and lattice excitations in the quasi-2D quantum spin compound (CuCl)LaNb2O7
Vladimir Gnezdilov1,2, Peter Lemmens1,3, Dirk Wulferding4, Atsushi Kitada5, and Hiroshi Kageyama6
1Institute for Condensed Matter Physics, TU Braunschweig, Braunschweig D-38106, Germany
2B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine Kharkiv 61103, Ukraine
3Laboratory of Emerging Nanometrology LENA, Braunschweig D-38106, Germany
4CCES, Inst. for Basic Science, Dept. Physics and Astronomy, Seoul Nat. Univ., Seoul 08826, Republic of Korea
5Department of Materials Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
6Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
Received June 29, 2021, published online September 24, 2021
Raman scattering phonon data of the quasi-two-dimensional quantum spin system (CuCl)LaNb2O7 are used to derive an effective structural model that may serve as a basis for its unconventional magnetic properties. Furthermore, a rich spectrum of magnetic excitations is observed, including quasielastic energy density fluctuations and finite energy bound states. These modes are the key to understand (CuCl)LaNb2O7 as a system with strong interactions between well-localized triplet excitations based on a pronounced competition of magnetic exchange.
Key words: quantum spin system, Raman scattering, magnetic and lattice excitations.