Partial ordering mechanisms in -electron systems

電子系における部分秩序機構

石飛 尊之

Ishitobi, Takayuki

This presentation focuses on partial ordering in frustrated systems. Partial orders typically arise as a three sublattice order in systems with frustration and Ising anisotropy. In this presentation, we present new mechanisms for stabilizing partial orders beyond Ising-type anisotropy. We show a partial quadrupole order with one-fourth disordered sites, stabilized by anisotropy unique to electric degrees of freedom. This partial order is robust at high temperatures within a framework of the Landau theory. This mechanism is an extension of the three-sublattice partial order with Ising anisotropy. We also discuss magnetic partial order mechanisms involving quadrupole moment interactions, where partial magnetic disorder persists even in quadrupole-ordered ground states. Finally, we examine a scenario with three partially magnetic ordered states due to quadrupole interactions, with potential applications to partially ordered state in UNiB.