Dimensional reduction by geometrical frustration in a cubic antiferromagnet composed of tetrahedral clusters

Abstract

Dimensionality is a critical factor in determining the properties of solids and is an apparent built-in character of the crystal structure. However, it can be an emergent and tunable property in geometrically frustrated spin systems. Here, we study the spin dynamics of the tetrahedral cluster antiferromagnet, pharmacosiderite, via muon spin resonance and neutron scattering. We find that the spin correlation exhibits a two-dimensional characteristic despite the isotropic connectivity of tetrahedral clusters made of spin 5/2 Fe3+ ions in the three-dimensional cubic crystal, which we ascribe to two-dimensionalisation by geometrical frustration based on spin wave calculations. Moreover, we suggest that even one-dimensionalisation occurs in the decoupled layers, generating low-energy and one-dimensional excitation modes, causing large spin fluctuation in the classical spin system. Pharmacosiderite facilitates studying the emergence of low-dimensionality and manipulating anisotropic responses arising from the dimensionality using an external magnetic field.

Supercritical CO2-induced anti-nanoconfinement effect to obtain novel 2D structures

“…According to the Mermin-Wagner theorem, continuous symmetry cannot be spontaneously broken so that the corresponding long-range ordering is prohibited at non-zero temperatures. 61,62 However, symmetry breaking, such as the occurrence of magnetic anisotropy, may remove this restriction. 63,64 An interesting phenomenon observed in non-vdW layered VO 2 (B) containing two vertically crossed tunnel-like frameworks c).…”

Emergence of Spinons in Layered Trimer Iridate Ba4Ir3O10

“…Consequently, some of the characteristic features for a 1D system are missing such as the Bonner-Fisher peak in susceptibility and bound state upon ordering. The 1D behavior is caused by the emergent dimensional reduction due to magnetic frustration, which has also been reported in other materials [63]. This raises an interesting question of whether the properties relevant to 2D QSLs are preserved in this case, which is yet to be explored.…”

Dimensional reduction in quantum spin-1/2 system on a 1/7-depleted triangular lattice

“…Here, we find another order-by-disorder phenomenon, a dimensional reduction effect, in a maple-leaf lattice antiferromagnet. The reduction of three-dimensionality of layered systems to effectively two-dimensions is previously reported both in theories and in experiments [20][21][22][23] , which is attributed to the competing frustrated interlayer interaction. In two dimensional systems, a onedimensional spinon-like continuum excitation is observed in a metal-organic square lattice antiferromagnet 24 as well as in the triangular lattice magnet 25,26 .…”