Correlated Partial Disorder in a Weakly Frustrated Quantum Antiferromagnet

M. G. Gonzalez, F. T. Lisandrini, G. G. Blesio, A. E. Trumper, C. J. Gazza, L. O. Manuel
2019 Physical Review Letters  
Partial disorder --the microscopic coexistence of long-range magnetic order and disorder-- is a rare phenomenon, that has been experimental and theoretically reported in some Ising- or easy plane-spin systems, driven by entropic effects at finite temperatures. Here, we present an analytical and numerical analysis of the S=1/2 Heisenberg antiferromagnet on the √(3)×√(3)-distorted triangular lattice, which shows that its quantum ground state has partial disorder in the weakly frustrated regime.
more » ... is state has a 180^∘ Néel ordered honeycomb subsystem, coexisting with disordered spins at the hexagon center sites. These central spins are ferromagnetically aligned at short distances, as a consequence of a Casimir-like effect originated by the zero-point quantum fluctuations of the honeycomb lattice.
doi:10.1103/physrevlett.122.017201 fatcat:ug2gtbob2fdcjb2vylemkeindy