Phase diagram and spin Hamiltonian of weakly-coupled anisotropic S=1/2 chains in CuCl2*2((CD3)2SO)

Abstract

Field-dependent specific heat and neutron scattering measurements were used to explore the antiferromagnetic S=1/2 chain compound CuCl2 * 2((CD3)2SO). At zero field the system acquires magnetic long-range order below TN=0.93K with an ordered moment of 0.44muB. An external field along the b-axis strengthens the zero-field magnetic order, while fields along the a- and c-axes lead to a collapse of the exchange stabilized order at mu0 Hc=6T and mu0 Hc=3.5T, respectively (for T=0.65K) and the formation of an energy gap in the excitation spectrum. We relate the field-induced gap to the presence of a staggered g-tensor and Dzyaloshinskii-Moriya interactions, which lead to effective staggered fields for magnetic fields applied along the a- and c-axes. Competition between anisotropy, inter-chain interactions and staggered fields leads to a succession of three phases as a function of field applied along the c-axis. For fields greater than mu0 Hc, we find a magnetic structure that reflects the symmetry of the staggered fields. The critical exponent, beta, of the temperature driven phase transitions are indistinguishable from those of the three-dimensional Heisenberg magnet, while measurements for transitions driven by quantum fluctuations produce larger values of beta.

arXiv commentrevtex 12 pages, 11 figures

References in corpus (17)

• Dynamics of coupled quantum spin chains
• Thermodynamics and spin gap of the Heisenberg ladder calculated by the look-ahead Lanczos algorithm
• Theory of the field-induced gap in $S=1/2$ antiferromagnetic chains
• On the Field-Induced Gap in Cu Benzoate and Other S=1/2 Antiferromagnets
• Direct Observation of Field-Induced Incommensurate Fluctuations in a One-Dimensional S=1/2 Antiferromagnet
• Extended quantum critical phase in a magnetized spin-1/2 antiferromagnetic chain
• Exact calculation of the ground-state dynamical spin correlation function of a S=1/2 antiferromagnetic Heisenberg chain with free spinons
• Dynamical Magnetic Susceptibilities in Cu Benzoate
• Bound spinons in an antiferromagnetic S=1/2 chain with a staggered field
• Exact two-spin dynamic structure factor of the one-dimensional s=1/2 Heisenberg-Ising antiferromagnet
• Sine-Gordon low-energy effective theory for Copper Benzoate
• Quantum Criticality in an Organic Magnet
• Coupled $S=1/2$ Heisenberg antiferromagnetic chains in an effective staggered field
• Dynamical T=0 correlations of the S=1/2 1D Heisenberg Anti-Ferromagnet with 1/r^2 exchange in a magnetic field
• Finite-temperature perturbation theory for quasi-one-dimensional spin-1/2 Heisenberg antiferromagnets
• Polarization dependence of spin excitations in BaCu2Si2O7
• The S=1/2 chain in a staggered field: High-energy bound-spinon state and the effects of a discrete lattice

Cited by in corpus (13)

• Quantum quench in the sine-Gordon model
• Field-induced magnetic phases and electric polarization in LiNiPO4
• Elementary excitations of S=1/2 one-dimensional antiferromagnet KCuGaF6 in magnetic field and quantum sine-Gordon model
• Magnetically-induced electric polarization in an organo-metallic magnet
• Dynamical Correlations of the Spin-1/2 Heisenberg XXZ Chain in a Staggered Field
• Thermodynamic properties of quantum sine-Gordon spin chain system KCuGaF6
• Magnetic order and ballistic spin transport in a sine-Gordon spin chain
• Low-energy properties of anisotropic two-dimensional spin-1/2 Heisenberg models in staggered magnetic fields
• Magnons and continua in a magnetized and dimerized spin-1/2 chain
• Anisotropic Field-Induced Gap in Quasi-One-Dimensional Antiferromagnet KCuMoO${}_4$(OH)
• Thermodynamics of a spin-1/2 XYZ Heisenberg chain with a Dzyaloshinskii-Moriya interaction
• High-field magnetic properties of the alternating ferro-antiferromagnetic spin-chain compound Cu${}_2$(OH)${}_3$Br
• Low-temperature thermal conductivity of antiferromagnetic S = 1/2 chain material CuCl_2$\cdot$2((CH_3)_2SO)