Electromagnon and phonon excitations in multiferroic TbMnO3
Abstract
We have performed Raman measurements on a TbMnO3 single crystal under magnetic field along the three crystallographic directions. The flip of the spin spiral plane creates an electromagnon excitation. In addition to the electromagnons induced by the Heisenberg coupling, we have detected the electromagnon created by the Dzyaloshinskii-Moriya interaction along the c axis. We have identified all the vibrational modes of TbMnO3. Their temperature dependencies show that only one phonon observed along the polarization axis is sensitive to the ferroelectric transition. This mode is tied to the Tb3+ ion displacements that contribute to the ferroelectric polarization.
- Publication:
-
Physical Review B
- Pub Date:
- July 2012
- DOI:
- 10.1103/PhysRevB.86.014437
- arXiv:
- arXiv:1207.5566
- Bibcode:
- 2012PhRvB..86a4437R
- Keywords:
-
- 75.85.+t;
- 75.50.Ee;
- 77.80.-e;
- 78.30.Hv;
- Antiferromagnetics;
- Ferroelectricity and antiferroelectricity;
- Other nonmetallic inorganics;
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- Phys. Rev. B 86, 014437 (2012)