Spin relaxation in Cs${}_2$CuCl${}_{4-x}$Br${}_x$

Abstract

The quantum-spin S = 1=2 chain system Cs${}_2$CuCl${}_4$ is of high interest due to competing anti-ferromagnetic intra-chain J and inter-chain exchange J' interactions and represents a paramount example for Bose-Einstein condensation of magnons [R. Coldea et al., Phys. Rev. Lett. 88, 137202 (2002)]. Substitution of chlorine by bromine allows tuning the competing exchange interactions and corresponding magnetic frustration. Here we report on electron spin resonance (ESR) in single crystals of Cs${}_2$CuCl${}_{4-x}$Br${}_x$ with the aim to analyze the evolution of anisotropic exchange contributions. The main source of the ESR linewidth is attributed to the uniform Dzyaloshinskii-Moriya interaction. The vector components of the Dzyaloshinskii-Moriya interaction are determined from the angular dependence of the ESR spectra using a high-temperature approximation. The obtained results support the site selectivity of the Br substitution suggested from the evolution of lattice parameters and magnetic susceptibility dependent on the Br concentration.

References in corpus (24)

• Experimental realization of a 2D fractional quantum spin liquid
• Direct Measurement of the Spin Hamiltonian and Observation of Condensation of Magnons in the 2D Frustrated Quantum Magnet Cs2CuCl4
• Bose-Einstein Condensation of Magnons in Cs2CuCl4
• Ordering in spatially anisotropic triangular antiferromagnets
• Extreme sensitivity of a frustrated quantum magnet: Cs_2CuCl_4
• Quantum stabilization of 1/3-magnetization plateau in Cs_2CuBr_4
• Modes of magnetic resonance in the spin liquid phase of Cs2CuCl4
• Direct determination of exchange parameters in Cs2CuBr4 and Cs2CuCl4: high-field ESR studies
• Magnetization plateaux of S = 1/2 two-dimensional frustrated antiferromagnet Cs${}_2$CuBr${}_4$
• The stable phases of the Cs2CuCl4-xBrx mixed systems
• Excitation spectra and ground state properties of the layered spin-1/2 frustrated antiferromagnets Cs_2CuCl_4 and Cs_2CuBr_4
• Dzyaloshinskii-Moriya coupling in 3d insulators
• Distinct magnetic regimes through site-selective atom substitution in the frustrated quantum antiferromagnet Cs${}_2$CuCl${}_{4-x}$Br${}_x$
• Magnetic resonance in the ordered phases of the 2D frustrated quantum magnet Cs2CuCl4
• Elastic constants and ultrasonic attenuation in the cone state of the frustrated antiferromagnet Cs_2CuCl_4
• Specific Heat Study of 1D and 2D Excitations in the Layered Frustrated Quantum Antiferromagnets Cs${}_2$CuCl${}_{4-x}$Br${}_x$
• Spin correlations and Dzyaloshinskii-Moriya interaction in Cs${}_2$CuCl${}_4$
• Nature of the low energy excitations in the short range ordered region of Cs${}_2$CuCl${}_4$ as revealed by ${}^{133}$Cs NMR
• Observation of new magnetic ground state in frustrated quantum antiferromagnet spin liquid system Cs2CuCl4
• High-field magnetic resonance of spinons and magnons in a triangular lattice S=1/2 antiferromagnet Cs2CuCl4
• Magnetic excitations in the spin-1/2 triangular-lattice antiferromagnet Cs${}_2$CuBr${}_4$
• Elastic constants and ultrasound attenuation in the spin-liquid phase of Cs${}_2$CuCl${}_4$
• Magneto-acoustic study near the quantum critical point of the frustrated quantum antiferromagnet Cs2CuCl4
• Magnetic phase diagram of the triangular antiferromagnetic $C{s}_{2}CuC{l}_{4-x}B{r}_x$ mixed system