Dimensional reduction by pressure in the magnetic framework material CuF${}_2$(D${}_2$O)${}_2$pyz: from spin-wave to spinon excitations

Abstract

Metal organic magnets have enormous potential to host a variety of electronic and magnetic phases that originate from a strong interplay between the spin, orbital and lattice degrees of freedom. We control this interplay in the quantum magnet CuF${}_2$(D${}_2$O)${}_2$pyz by using high pressure to drive the system through a structural and magnetic phase transition. Using neutron scattering, we show that the low pressure state, which hosts a two-dimensional square lattice with spin-wave excitations and a dominant exchange coupling of 0.89 meV, transforms at high pressure into a one-dimensional spin-chain hallmarked by a spinon continuum and a reduced exchange interaction of 0.43 meV. This direct microscopic observation of a magnetic dimensional crossover as a function of pressure opens up new possibilities for studying the evolution of fractionalised excitations in low dimensional quantum magnets and eventually pressure-controlled metal--insulator transitions.

References in corpus (6)

• Dimensional reduction at a quantum critical point
• Fractional excitations in the square-lattice quantum antiferromagnet
• Anomalous High-Energy Spin Excitations in La2CuO4
• Quantum and classical criticality in a dimerized quantum antiferromagnet
• Isotope effect in quasi-two-dimensional metal-organic antiferromagnets
• Magnetic properties of the S=1/2 quasi square lattice antiferromagnet CuF2(H2O)2(pyz) (pyz=pyrazine) investigated by neutron scattering

Cited by in corpus (2)

• Pressure-tuning the quantum spin Hamiltonian of the triangular lattice antiferromagnet Cs${}_2$CuCl${}_4$
• One dimensionalization in the spin-1 Heisenberg model on the anisotropic triangular lattice