Magnon Condensation in Dimerized Antiferromagnets with Spin-Orbit Coupling

Abstract

Bose-Einstein condensation (BEC) of triplet excitations triggered by a magnetic field, sometimes called magnon BEC, in dimerized antiferromagnets gives rise to a long-range antiferromagnetic order in the plane perpendicular to the applied magnetic field. To explore the effects of spin-orbit coupling on magnon condensation, we study a spin model on a distorted honeycomb lattice with dimerized Heisenberg exchange ($J$ terms) and uniform off-diagonal exchange (${\Gamma }^{\prime }$ terms) interactions. Via variational Monte Carlo calculations and spin-wave theory, we find that an out-of-plane magnetic field can induce different types of long-range magnetic orders, no matter if the ground state is a non-magnetic dimerized state or an ordered Néel state. Furthermore, the critical properties of field-driven phase transitions in the presence of spin-orbit couplings, as illustrated from spin-wave spectrum and interpreted by effective field theory, can be different from the conventional magnon BEC. Our study is helpful to understand the rich phases of spin-orbit coupled antiferromagnets induced by magnetic fields.

References in corpus (19)

• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• $\alpha$-RuCl3: a Spin-Orbit Assisted Mott Insulator on a Honeycomb Lattice
• Bose-Einstein Condensation in Magnetic Insulators
• Fractional excitations in the square-lattice quantum antiferromagnet
• Hidden symmetries of the extended Kitaev-Heisenberg model: Implications for honeycomb lattice iridates A2IrO3
• Magnetization processes of zigzag states on the honeycomb lattice: Identifying spin models for $\alpha$-RuCl${}_3$ and Na${}_2$IrO${}_3$
• Honeycomb-lattice Heisenberg-Kitaev model in a magnetic field: Spin canting, metamagnetism, and vortex crystals
• Magnetic anisotropy in the Kitaev model systems Na2IrO3 and RuCl3
• Identification of Magnetic Interactions and High-field Quantum Spin Liquid in $\alpha$-RuCl${}_3$
• Multiple Magnon Modes and Consequences for the Bose-Einstein Condensed Phase in BaCuSi2O6
• High-pressure magnetization and NMR studies on $\alpha$-RuCl${}_3$
• Geometric Frustration and Dimensional Reduction at a Quantum Critical Point
• Consequences of spin-orbit coupling for the Bose-Einstein condensation of magnons
• Emergent Symmetry and Dimensional Reduction at a Quantum Critical Point
• Rare-earth chalcohalides: A family of van der Waals layered Kitaev spin liquid candidates
• NMR evidence for a strong modulation of the Bose-Einstein Condensate in BaCuSi${}_2$O${}_6$
• Reduced dimensionality in layered quantum dimer magnets: Frustration vs. inhomogeneous condensates
• Response of a strongly interacting spin-orbit coupling system to a Zeeman field
• Thermal Properties and Instability of a $U(1)$ Spin Liquid on the Triangular Lattice

Cited by in corpus (5)

• Beyond Kitaev physics in strong spin-orbit coupled magnets
• Bose-Einstein condensation in honeycomb dimer magnets and $\mathrm{Y}{\mathrm{b}}_2\mathrm{S}{\mathrm{i}}_2{\mathrm{O}}_7$
• Sinusoidal magnetic field induced topological excitations in a spin-orbit coupled spinor condensate
• Bose-Einstein condensations of magnons in quantum magnets with spin-orbit coupling in a Zeeman field
• Ground state of the staggered Heisenberg-$\Gamma$ honeycomb model in a magnetic field