Regensburg 2016 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 34: Correlated Electrons: Frustrated Magnets - Chiral Magnets & RuCl3
TT 34.5: Vortrag
Dienstag, 8. März 2016, 15:00–15:15, H20
Critical dynamics in LiCuVO4 — •Christoph Grams1, Petra Becker2, and Joachim Hemberger1 — 1II. Physikalisches Institut, Universität zu Köln, Germany — 2Institut für Kristallographie, Universität zu Köln, Germany
Without an external magnetic field the 1D spin chain compound LiCuVO4 has a phase transition into a cycloidal spin ordered phase below TN = 2.3 K where it simultaneously is antiferromagnetic and ferroelectric. The transition temperature of this phase transition can be lowered with increasing magnetic field. Ferroelectric phase transitions are of continuous type and are accompanied by a symmetry lowering that yields soft modes. Near the critical point the dynamics show a “critical slowing down” scenario.
We studied the magnetic field and temperature dependence of ε(ν) in LiCuVO4 in the vicinity of the multiferroic phase transition by means of broadband dielectric spectroscopy. While we find the expected relaxational behavior close to TN, below 0.4 K a nearly gapless excitation is observed as was theoretically predicted in terms of chiral solitons [1].
Funded through the Institutional Strategy of the University of Cologne within the German Excellence Initiative.
[1] S. Furukawa et al., JPSJ 77, 123712 (2008)