23 research outputs found
Quantum gapped state in a spin-1/2 distorted honeycomb-based lattice with frustration
We successfully synthesized (-Py-V)[Cu(hfac)], a verdazyl-based
complex. Molecular orbital calculations revealed five types of intermolecular
interactions between the radical spins and two types of intramolecular
interactions between the radical and the Cu spins, resulting in a spin-1/2
distorted honeycomb-based lattice. Additionally, competing ferromagnetic and
antiferromagnetic (AF) interactions induce frustration. The magnetization curve
displayed a multistage increase, including a zero-field energy gap. Considering
the stronger AF interactions that form dimers and tetramers, the magnetic
susceptibility and magnetization curves were qualitatively explained. These
findings demonstrated that the quantum state, based on the dominant AF
interactions, was stabilized due to the effects of frustration in the lattice.
Hence, the exchange interactions forming two-dimensional couplings decoupled,
reducing energy loss caused by frustration and leading to frustration-induced
dimensional reduction.Comment: 6 pages, 5 figure
Field-induced quantum phase in a frustrated zigzag-square lattice
This study presents the experimental realization of a spin-1/2 zigzag-square
lattice in a verdazyl-based complex, namely
(-Py-V-2,6-F)Cu(hfac). Molecular orbital calculations suggest
the presence of five types of frustrated exchange couplings. Our observations
reveal an incremental increase in the magnetization curve beyond a critical
field, signifying a phase transition from the antiferromagnetic ordered state
to a quantum state characterized by a 1/2 plateau. This intriguing behavior
arises from the effective stabilization of a zigzag chain by the external
fields. These results provide evidence for field-induced dimensional reduction
in a zigzag-square lattice attributed to the effects of frustration.Comment: 5 pages, 4 figure