Temperature dependent spin gap in multiferroic 2D-XY antiferromagnet Ba2CoGe2O7 under applied magnetic field

IEEE International Magnetic Conference - Short Papers (INTERMAG Short Papers), pp. 1–2

Abstract

We report an inelastic neutron scattering study on the low-energy magnetic excitations of Ba2CoGe2O7single crystals under applied magnetic fields for several fixed temperatures. Recently, a spin gap of about 0.1 meV has been observed under zero magnetic field and interpreted as an effect of spin-nematic interaction [1]. However, we have predicted such gap via linear spin wave theory by introducing the Dzyaloshinskii–Moriya interaction in the spin Hamiltonian. We have observed a spin gap of 0.105 meV in energy at 2 K under zero magnetic field and the gap energy decreases with increasing temperature. Temperature dependent spin gap also evolves under an applied magnetic field. Our results enlighten the discussion on understanding the origin of the zero-field spin gap in details.

Authors 9

1. Rajesh Dutta Aachen Institut für Kristallographie

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen Universität,Institut für Kristallographie,Aachen,Germany,52066

2. Henrik Thoma Aachen Institut für Kristallographie

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen Universität,Institut für Kristallographie,Aachen,Germany,52066

3. B. Roessli

   Paul Scherrer Institute

   Affiliation as printed

   Paul Scherrer Institut (PSI),Laboratory for Neutron Scattering and Imaging (LNS),Villigen PSI,Switzerland,5232

4. Vilmos Kocsis

   RIKEN Center for Emergent Matter Science

   Affiliation as printed

   RIKEN Center for Emergent Matter Science (CEMS),Wako, Saitama,Japan,351-0198

5. Y. Tokunaga

   RIKEN Center for Emergent Matter Science · The University of Tokyo

   Affiliation as printed

   RIKEN Center for Emergent Matter Science (CEMS),Wako, Saitama,Japan,351-0198

   Department of Advanced Materials Science, University of Tokyo, Kashiwa, Japan

6. Y. Taguchi

   RIKEN Center for Emergent Matter Science

   Affiliation as printed

   RIKEN Center for Emergent Matter Science (CEMS),Wako, Saitama,Japan,351-0198

7. Yoshinori Tokura

   RIKEN Center for Emergent Matter Science · The University of Tokyo

   Affiliation as printed

   RIKEN Center for Emergent Matter Science (CEMS),Wako, Saitama,Japan,351-0198

   Department of Applied Physics, Quantum-Phase Electronics Center, University of Tokyo, Hongo, Tokyo, Japan

8. I. Kézsmárki

   University of Augsburg

   Affiliation as printed

   University of Augsburg,Department of Experimental Physics V,Augsburg,Germany,86159

9. Vladimir M. Hutanu Aachen Institut für Kristallographie

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen Universität,Institut für Kristallographie,Aachen,Germany,52066