Temperature renormalization of the magnetic excitations in S = 1/2 KCuCl3

Cavadini, N.; Rüegg, Ch.; Henggeler, Wolfgang; Furrer, A.; Güdel, Hans-Ulrich; Krämer, Karl; Mutka, H. (2000). Temperature renormalization of the magnetic excitations in S = 1/2 KCuCl3. European physical journal. B - condensed matter and complex systems, 18(4), pp. 565-571. EDP Sciences 10.1007/s100510070003

Text s100510070003.pdf - Published Version Restricted to registered users only Available under License Publisher holds Copyright. Download (217kB) | Request a copy

A complete temperature characterization of the spin dynamics in the unconventional S =1/2 antiferromagnet KCuCl3 is presented from single crystal inelastic neutron scattering studies. KCuCl3 features a quantum disordered singlet ground state with a finite spin gap to triplet excitations of dimer origin. Three dimensional magnetic correlations support the dispersive propagation of the excitations in the whole reciprocal space. Upon increasing the temperature, a renormalization in the energy, in the intensity and in the damping rate of the triplet modes is reported. The experimental observations can be described within the framework of a selfconsistent dimer RPA theory, with no free parameters. The driving mechanism behind the model is the thermally activated decrease of the occupation difference n 0 - n 1 between singlet and triplet dimer states. This is the expression of kinematic constraints which are of minor importance for classical magnons in Néel ordered antiferromagnets. Implications for the temperature dependence of macroscopic quantities are discussed.

Interest & Impact

Downloads

1 since deposited on 18 Jan 2016
1 in the past 12 months

Citations

5 Citations in Web of Science ®
6 Citations in Scopus

Search

in Google Scholar™

Services

Actions (login required)

Edit item

Actions (login required)

Edit item