The spin dynamics in distorted kagome lattices: a comparative Raman study

Abstract

Despite the conceptional importance of realizing spin liquids in solid states only few compounds are known. On the other hand the effect of lattice distortions and anisotropies on the magnetic exchange topology and the fluctuation spectrum is an interesting problem. We compare the excitation spectra of the two s = 1/2 kagome lattice compounds, volborthite and vesignieite, using Raman scattering. We demonstrate that even small modifications of the crystal structure may have a huge effect on the phonon spectrum and low-temperature properties.

Theory of Raman response in three-dimensional Kitaev spin liquids: Application toβ- andγ−Li2IrO3compounds

“…However, one distinctive feature of topological order that can be probed by conventional methods, 21 such as inelastic neutron 17,[22][23][24][25][26] or Raman scattering [27][28][29] , is fractionalization. In quantum spin liquids there are elementary (chargeless) excitations carrying fractional quantum numbers relative to the local constituent degrees of freedom (charged electrons and spin 1 magnons).…”

“…27), or are linearly related to these ones by Eqs. (28)(29). In particular, B 3g is degenerate with B 2g .…”

Lattice and magnetic instabilities in Cu3Bi(SeO3)2OGnezdilov1, Pashkevich2, Lemmens3 et al. 2017Phys. Rev. B235190View full textAdd to dashboardCite

“…7 , 8 Recently, this technique has been successfully applied to characterize the excitation spectrum of the spin liquid state in a Heisenberg S = 1/2 antiferromagnet on a perfect kagome lattice -herbertsmithite ZnCu 3 (OH) 6 2 ) with slightly distorted, kagome planes demonstrate that even small modifications of the crystal structure may have a huge effect on its properties. 10 Here, we report on a detailed study of the temperature dependence of the vibrational and magnetic excitations in Cu 3 Bi(SeO 3 ) 2 O 2 X (X = Cl, Br). Data analysis allows us to affirm that the second order phase transition at T* = 120 K in Cu 3 Bi(SeO 3 ) 2 O 2 Cl occurs with a loss of inversion symmetry.…”

Spin-12Heisenberg antiferromagnet on an anisotropic kagome lattice

“…A spatially anisotropic version of the spin-1 2 kagome HAF has also been suggested to have been realized experimentally in the minerals vorborthite Cu 3 V 2 O 7 (OH) 2 •2H 2 O (Refs. [60][61][62][63][64][65][66] and vesignieite BaCu 3 (VO 4 ) 2 (OH) 2 . 64,[66][67][68][69] In both of these materials, the Cu sites form a slightly distorted kagome network, resulting in two inequivalent Cu sites per triangle, namely, one Cu1 site and two Cu2 sites per triangle.…”