risb

Official Resources

• Source Repository: https://github.com/thenoursehorse/risb
• License: GPL-3.0

Overview

risb is a code package for solving strongly correlated many-body electronic problems using the Rotationally Invariant Slave Bosons (RISB) method. This auxiliary particle method captures key features of correlations (like the Mott transition) at a computational cost comparable to mean-field theories, making it significantly faster than full DMFT.

Scientific domain: Strongly correlated lattice models, Mean-field approximations Target user community: Researchers studying model Hamiltonians, Mott transitions

Theoretical Methods

• Rotationally Invariant Slave Bosons (RISB)
• Mean-Field Theory
• Auxiliary Particle Method
• Hubbard Model / Anderson Lattice

Capabilities

• Solving strongly correlated lattice models
• Describing the Mott Metal-Insulator Transition
• Calculating quasiparticle renormalization factors (Z)
• Evaluating ground state energies and occupancies

Key Strengths

Speed vs. Physics:

• Captures the Mott transition (unlike HF) but is much faster than DMFT.

Rotational Invariance:

• Can handle general local interactions and orbital mixing correctly.

Tutorials:

• Repository includes examples/tutorials for common lattice models.

Inputs & Outputs

• Input formats:
  • Model parameters (lattices, U, t)
• Output data types:
  • Order parameters
  • Renormalization factors
  • Energies

Interfaces & Ecosystem

• Language: Python (likely, based on typical research codes in this domain).

Advanced Features

• Lattice Models: Built-in support for common lattices.

Performance Characteristics

• Efficiency: High. Solves non-linear algebraic equations rather than integral equations (like DMFT) or massive Hamiltonians (like ED).

Computational Cost

• Low: Accessible on standard workstations.

Limitations & Known Constraints

• Dynamics: Static approximation (frequency independent self-energy at low energy).
• finite-T: Usually formulated for T=0 or low T.

Comparison with Other Codes

• vs CyGutz: Similar method (RISB/Gutzwiller are related).
• vs DMFT: risb is the "infinite dimensions" mean-field limit without dynamics.

Verification & Sources

Primary sources:

1. GitHub: https://github.com/thenoursehorse/risb

Verification status: ✅ VERIFIED

• Source code: OPEN