The Role of Magnetic Dipole—Dipole Coupling in Quantum Single-Molecule Toroics

For single-molecule toroics (SMTs) based on noncollinear Ising spins, intramolecular magnetic dipole–dipole coupling favours a head-to-tail vortex arrangement of the semi-classical moments associated with toroidal ground state. However, to what extent does this effect survive beyond limit? Here, we theoretically investigate role dipolar interactions in stabilising ground-state quantum Heisenberg rings and without on-site anisotropy. prototypical triangular SMT strong anisotropy, illustrate that, together exchange, serves preserve toroidicity. In addition, tunnelling moment Kramers non-Kramers systems. weak anisotropy limit, find within some critical ion–ion distances, interactions, diagonalised over entire Hilbert space system, recover toroidicity ferromagnetic antiferromagnetic odd-membered up seven sites, are further stabilised by Dzyaloshinskii–Moriya coupling.