Switching the Magnetization in Quantum Antiferromagnets

Abstract

The orientation of the order parameter of quantum magnets can be used to store information in a dense and efficient way. Switching this order parameter corresponds to writing data. To understand how this can be done, we study a precessional reorientation of the sublattice magnetization in an (an)isotropic quantum antiferromagnet induced by an applied magnetic field. We use a description including the leading quantum and thermal fluctuations, namely Schwinger boson mean-field theory, because this theory allows us to describe both ordered phases and the phases in between them, as is crucial for switching. An activation energy has to be overcome requiring a minimum applied field $h_{\text{t}}$ which is given essentially by the spin gap. It can be reduced significantly for temperatures approaching the Néel temperature facilitating switching. The time required for switching diverges when the field approaches $h_{\text{t}}$ which is the signature of an inertia in the magnetization dynamics. The temporal evolution of the magnetization and of the energy reveals signs of dephasing. The switched state has lost a part of its coherence because the magnetic modes do not evolve in phase.

arXiv comment19 pages, 20 figures

References in corpus (19)

• Antiferromagnetic spintronics
• Electrical switching of an antiferromagnet
• Relativistic Neel-order fields induced by electrical current in antiferromagnets
• Spin transfer and current-induced switching in antiferromagnets
• Spin-waves in triangular lattice antiferromagnet: decays, spectrum renormalization, and singularities
• Concepts of antiferromagnetic spintronics
• Full angular dependence of the spin Hall and ordinary magnetoresistance in epitaxial antiferromagnetic NiO(001)/Pt thin films
• Ultrafast Switching of Antiferromagnets via Spin-transfer Torque
• Magnetic and quantum disordered phases in triangular-lattice Heisenberg antiferromagnets
• SU(N) Irreducible Schwinger Bosons
• Magnons and Excitation Continuum in XXZ triangular antiferromagnetic model: Application to $B{a}_{3}CoS{b}_2{O}_9$
• Magnetoresistance effects in the metallic antiferromagnet Mn${}_2$Au
• Schwinger boson theory of anisotropic ferromagnetic ultrathin films
• Optical read-out of the Néel vector in metallic antiferromagnet Mn${}_2$Au
• Schwinger boson theory of ordered magnets
• Ferromagnetic frustrated spin systems on the square lattice: a Schwinger boson study
• The $1/N$ Expansion and Spin Correlations in Constrained Wavefunctions
• Pathology of Schwinger boson mean field theory for Heisenberg spin models
• Continuous similarity transformation for critical phenomena: easy-axis antiferromagnetic XXZ model

Cited by in corpus (7)

• Terahertz high-harmonic generation in gapped antiferromagnetic chains
• Switching of Magnetization in Quantum Antiferromagnets with Time-Dependent Control Fields
• Exchange enhanced switching by alternating fields in quantum antiferromagnets
• Cavity-assisted magnetization switching in a quantum spin-phonon chain
• Landau-Lifshitz damping from Lindbladian dissipation in quantum magnets
• Switching magnetization of quantum antiferromagnets: Schwinger boson mean-field theory compared to exact diagonalization
• Multimagnon and multispinon $L_3$-edge RIXS spectra of an effective ${\tilde{J}}_1-{\tilde{J}}_2-{\tilde{J}}_3$ square lattice Heisenberg model