Dimensional change of the quadrupole order in pseudospin- 12 pyrochlore magnets under magnetic field in the [111] direction
| Autor: | Hiroaki Kadowaki, Mika Wakita, Hiroshi Takatsu |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Physics
Phase transition Condensed matter physics Pyrochlore 02 engineering and technology engineering.material 021001 nanoscience & nanotechnology 01 natural sciences Magnetic field symbols.namesake Paramagnetism Ferromagnetism Lattice (order) 0103 physical sciences Quadrupole engineering symbols Condensed Matter::Strongly Correlated Electrons 010306 general physics 0210 nano-technology Hamiltonian (quantum mechanics) |
| Zdroj: | Physical Review B. 98 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.98.144410 |
| Popis: | We have studied long-range orders of electric quadrupole moments described by an effective pseudospin-$\frac{1}{2}$ Hamiltonian representing pyrochlore magnets with non-Kramers ions under [111] magnetic field, in relevance to ${\mathrm{Tb}}_{2}{\mathrm{Ti}}_{2}{\mathrm{O}}_{7}$. Order parameters and phase transitions of this frustrated system are investigated using classical Monte Carlo simulations. In zero field, the model undergoes a first-order phase transition from a paramagnetic state to an ordered state with an antiparallel arrangement of pseudospins. This pseudospin order is characterized by the wave vector $\mathbit{k}=0$ and is selected by an energetic or an order-by-disorder mechanism from degenerate $\mathbit{k}=(h,h,h)$ mean-field orders. Under [111] magnetic field this three-dimensional quadrupole order is transformed to a quasi-two-dimensional quadrupole order on each kagome lattice separated by field-induced ferromagnetic triangular lattices. We discuss the implication of the simulation results with respect to experimental data of ${\mathrm{Tb}}_{2}{\mathrm{Ti}}_{2}{\mathrm{O}}_{7}$. |
| Databáze: | OpenAIRE |
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