Exact diagonalization for spin-1/2 spin ice pyrochlores

TL;DR

This paper provides exact solutions for a 16-site spin-1/2 pyrochlore model using group theory, revealing detailed symmetry properties and identifying a perturbed spin ice phase at low temperatures.

Contribution

It introduces an exact diagonalization approach combined with symmetry analysis to study quantum spin ice states in a finite pyrochlore lattice.

Findings

Exact eigenstates and eigenvalues for the 16-site model

Identification of a perturbed spin ice phase at low temperatures

Symmetry classification of spin ice states

Abstract

We find exact solutions to the Hamiltonian of a 16-site spin-1/2 pyrochlore crystal with nearest neighbour exchange interactions. The methods of group theory (symmetry) are used to completely block-diagonalize the Hamiltonian, yielding precise details about symmetry of the eigenstates, in particular those components which are {\em spin ice} states, in order to evaluate the spin ice density at finite temperature. At low enough temperatures, a `perturbed' spin ice phase is clearly outlined within the four parameter space of the general model of exchange interactions. The quantum spin ice phase is expected to exist outside these boundaries.