Resonating valence bond wave functions for strongly frustrated spin systems

Area of Science:

• Condensed Matter Physics
• Quantum Magnetism

Background:

• Resonating-valence-bond (RVB) theory describes quantum antiferromagnets.
• Quantum frustration is a key factor in these systems.
• Microscopic confirmation of RVB theory under frustration has been lacking.

Purpose of the Study:

• To confirm the validity of the resonating-valence-bond (RVB) theory in two-dimensional quantum antiferromagnets.
• To investigate the role of quantum frustration in stabilizing the RVB state.
• To identify a variational wave function that accurately represents the RVB ground state.

Main Methods:

• Development and application of a new type of variational wave function.
• Analysis of the J(1)-J(2) Heisenberg model for spin-half systems.
• Comparison of the variational wave function to exact ground states.

Main Results:

• The new variational wave function closely approximates the exact ground state of the J(1)-J(2) Heisenberg model within a specific frustration regime (0.4 < J(2)/J(1) < 0.5).
• This provides strong microscopic support for the resonating-valence-bond (RVB) theory in the presence of significant quantum frustration.
• The proposed wave function is suggested to represent the generic spin-half RVB ground state in spin liquids.

Conclusions:

• The resonating-valence-bond (RVB) theory is validated as the correct paradigm for two-dimensional quantum antiferromagnets with sufficient quantum frustration.
• A novel variational wave function offers a highly accurate representation of the RVB ground state.
• This work advances the understanding of spin liquids and quantum magnetism.