Finite-Temperature Transition in the Spin-Dimer Antiferromagnet BaCuSi2O6

Abstract

We consider a classical XY-like Hamiltonian on a body-centered tetragonal lattice, focusing on the role of interlayer frustration. A three-dimensional (3D) ordered phase is realized via thermal fluctuations, breaking the mirror-image reflection symmetry in addition to the XY symmetry. A heuristic field-theoretical model of the transition has a decoupled fixed point in the 3D XY universality, and our Monte Carlo simulation suggests that there is such a temperature region where long-wavelength fluctuations can be described by this fixed point. However, it is shown using scaling arguments that the decoupled fixed point is unstable against a fluctuation-induced biquadratic interaction, indicating that a crossover to nontrivial critical phenomena with different exponents appears as one approaches the critical point beyond the transient temperature region. This new scenario clearly contradicts the previous notion of the 3D XY universality.

16 pages, 7 figures

References in corpus (12)

• Bose-Einstein Condensation in Magnetic Insulators
• Dimensional reduction at a quantum critical point
• Characteristic BEC scaling close to Quantum Critical Point in BaCuSi2O6
• Multiple Magnon Modes and Consequences for the Bose-Einstein Condensed Phase in BaCuSi2O6
• Geometric Frustration and Dimensional Reduction at a Quantum Critical Point
• Emergent Symmetry and Dimensional Reduction at a Quantum Critical Point
• Theory of the field-induced BEC in the frustrated spin-1/2 dimer compound BaCuSi2O6
• NMR evidence for a strong modulation of the Bose-Einstein Condensate in BaCuSi${}_2$O${}_6$
• Low temperature structural phase transition and incommensurate lattice modulation in the spin gap compound BaCuSi2O6
• Harmonic crossover exponents in O(n) models with the pseudo-epsilon expansion approach
• Quantum phase transitions and dimensional reduction in antiferromagnets with inter-layer frustration
• Reduced dimensionality in layered quantum dimer magnets: Frustration vs. inhomogeneous condensates

Cited by in corpus (7)

• Formation of Magnetic Microphases in Ca${}_3$Co${}_2$O${}_6$
• Dimensional crossover in the quasi-two-dimensional Ising-O(3) model
• Multiple Magnetic Bilayers and Unconventional Criticality without Frustration in BaCuSi${}_2$O${}_6$
• Crossover Behavior from Decoupled Criticality
• Stable Higgs mode in anisotropic quantum magnets
• Non-monotonic Dynamics in Frustrated Ising Model with Time-Dependent Transverse Field
• Critical and multicritical behavior in the Ising-Heisenberg universality class