Competing interaction induced phase diagram and phase transition in artificial triangular spin ice

Competing interactions are the simultaneous presence of conflicting coupling forces in a system, which can lead to the emergence of rich physical properties and phenomena. We have studied artificial spin ices composed of single-domain nanomagnets on triangular arrays using magnetic force microscopy and Monte Carlo simulations. A phase diagram with three distinct phases is obtained analytically through tuning the interaction between local neighboring spins continuously. These phases and phase boundaries are precisely reproduced by experimental data, providing strong evidence for the success of our theoretical model. Further to this, a subsequent study reveals that incorporating long-range interactions results in different phase boundaries. This conclusion is further confirmed by another experiment where a phase transition behavior is observed when the spin correlation within the system exceeds the neighbors within a triangular vertex. These findings indicate that further neighbor interactions in artificial triangular array can significantly affect the magnetic phases of the system, showing significant differences from other geometry-based artificial spin ices.