Is solid copper oxalate a spin chain or a mixture of entangled spin pairs?

Abstract

Macroscopic assemblies of interacting spins give rise to a broad spectrum of behaviors determined by the spatial arrangement of the magnetic sites and the electronic interactions between them. Compounds of copper (II), in which each copper carries spin $\frac{1}{2}$, exhibit a vast variety of physical properties. For antiferromagnetically coupled spin sites, there are two limiting scenarios: spin chains in which the spins can exhibit a long-range order or a mixture of dimers in which the spins within each pair are entangled but do not communicate with the spins from other dimers. In principle, the two types can be distinguished on the basis of experimental observations and modeling using empirically parameterized effective Hamiltonians, but in practice, ambiguity may persist for decades, as is the case for copper oxalate. Here we use high-level ab initio calculations to establish the validity of the nearest-site Heisenberg model and to predict the interaction strength between the magnetic sites. The computed magnetic susceptibility provides an unambiguous interpretation of magnetic experiments performed throughout half a century, clearly supporting the infinite spin-chain behavior of solid copper oxalate.

References in corpus (12)

• Antiferromagnetic spintronics
• Quantum criticality
• Thermodynamics of Spin S = 1/2 Antiferromagnetic Uniform and Alternating-Exchange Heisenberg Chains
• Fractional spinon excitations in the quantum Heisenberg antiferromagnetic chain
• Computation of dynamical correlation functions of Heisenberg chains: the gapless anisotropic regime
• Helicoidal magnetic order in a clean copper oxide spin chain compound
• Thermodynamics of quantum Heisenberg spin chains
• Quantum criticality in the spin-$1/2$ Heisenberg chain system copper pyrazine dinitrate
• Dynamically dominant excitations of string solutions in the spin-1/2 antiferromagnetic Heisenberg chain in magnetic fields
• Magnetic properties of a S=1/2 zigzag spin chain compound (N_2H_5)CuCl_3
• Luttinger-Liquid Behavior in the Alternating Spin-Chain System Copper Nitrate
• New superexchange paths due to breathing-enhanced hopping in corner-sharing cuprates

Cited by in corpus (4)

• Interpretation of multiple solutions in fully iterative GF2 and GW schemes using local analysis of two-particle density matrices
• Broken-symmetry self-consistent GW approach: degree of spin contamination and evaluation of effective exchange couplings in solid antiferromagnets
• The $S$-diagnostic -- an a posteriori error assessment for single-reference coupled-cluster methods
• Natural orbitals and two-particle correlators as tools for analysis of effective exchange couplings in solids