Spin‐singlet Quantum Ground State in Zigzag Spin Ladder Cu(CF₃COO)₂

Abstract

The copper salt of trifluoroacetic acid, Cu(CF COO) , offers a new platform to investigate the quantum ground states of low-dimensional magnets. In practice, it realizes the ideal case of a solid hosting essentially isolated magnetic monolayers. These entities are constituted by well-separated two-leg half-integer spin ladders organized in a zigzag fashion. The ladders are comprised of dimeric units of edge-sharing tetragonal pyramids coupled through carbon ions. The spin-gap state in this compound was revealed by static and dynamic magnetic measurements. No indications of long range magnetic ordering down to liquid helium temperature were obtained in specific heat measurements. First principles calculations allow estimation of the main exchange interaction parameters, J =176 K and J =12 K, consistent with the weakly interacting dimers model.

Approaching the isotropic spin-ladder regime: structure and magnetism of all-pyrazine-bridged copper(ii)-based antiferromagnetic ladders

“…The spin gap was also estimated in this study for 1 and 2 using various methods. The energy gap Δ separating the S = 0 ground state from the first S = 1 excited state is approximately equal to |0.5·2 J | 3,4 giving | Δ | = 5.8 K ( 2 ), 5.6 K ( 1 ) based on the isotropic J values J rail = J rung = −5.51 K ( 1 ) and −5.91 K ( 2 ). According to the expression in second order J rail / J rung from Ref.…”

“…Spin ladder systems have been of interest since theoretical predictions intended to describe the low-dimensional magnetic behavior of some potentially superconducting copperoxide compounds revealed a rich magnetic excitation spectrum. [1][2][3] The synthesis of copper(II) molecular lattices comprising ladders has since been pursued [4][5][6][7] as weakly interacting analogs enabling field dependent investigations of the magnetic spectrum, ideally to saturation in an applied field of <20 T. These molecular systems have provided insightful probes into the ladder phase diagram as a function of the exchange strengths within the ladders and between ladders. 8,9,[10][11][12] Chemists have, over the decades, developed experimental scaffolding techniques to engineer complexes with weak antiferromagnetic interactions restricted to two or fewer dimensions.…”

Thermal Properties of Rung Disordered Two-leg Quantum Spin Ladders: Quantum Monte Carlo Study

“…Various properties of a wide range of different ladder models have been studied, like spin ladder systems with dimerization [35][36][37][38][39][40][41] , zig-zag ladders 23,[42][43][44][45] , mixed ladders [46][47][48][49][50] . A gapless phase has been found in two-leg zig-zag ladders with frustration by benefiting from exact diagonalization and density matrix renormalization group (DMRG) methods 23 .…”

“…A ferrimagnetic spin-1 and spin-1/2 mixed spin ladder has been analyzed by using spin-wave theory and bosonization techniques 48 . Thermal and ground state properties of the similar ladder systems have been also studied by appliying QMC methods 38,40,45 . The presence of quenched bond randomness may significantly affect the thermal and magnetic properties of the considered system even at low disorder concentration values.…”