Dilution Effects in Two-dimensional Quantum Orbital System

Abstract

We study dilution effects in a Mott insulating state with quantum orbital degree of freedom, termed the two-dimensional orbital compass model. This is a quantum and two-dimensional version of the orbital model where the interactions along different bond directions cause frustration between different orbital configurations. A long-range correlation of a kind of orbital at each row or column, termed the directional order, is studied by means of the quantum Monte-Carlo method. It is shown that decrease of the ordering temperature due to dilution is much stronger than that in spin models. Quantum effect enhances the effective dimensionality in the system and makes the directional order robust against dilution. We discuss an essential mechanism of the dilute orbital systems.

5pages, 4 figures

References in corpus (1)

• Orbital order in classical models of transition-metal compounds

Cited by in corpus (9)

• First order phase transition in the anisotropic quantum orbital compass model
• Monte Carlo simulations of the directional-ordering transition in the two-dimensional classical and quantum compass model
• Absence of Hole Confinement in Transition Metal Oxides with Orbital Degeneracy
• Doubly degenerate orbital system in honeycomb lattice: implication of orbital state in layered iron oxide
• Quantum phase transition in the one-dimensional period-two and uniform compass model
• Orbital order driven quantum criticality
• Dilution effect in correlated electron system with orbital degeneracy
• Finite-Temperature Néel Ordering of Fluctuations in a Plaquette Orbital Model
• Thermal Canting of Spin-Bond Order