qlinks

qlinks is a research-oriented Python package for constrained lattice Hamiltonians, Fock-space graph diagnostics, interference-cage searches, and open-system constructions around many-body scarred states.

The package is designed around a typical exact-diagonalization workflow: choose a lattice model, build the constrained basis and Hamiltonian, analyze its Fock-space structure, and then use visualization or diagnostic tools to understand compact and regional cage states.

Warning

The public API is becoming more stable, but the caging and open-system layers are still active research code. Prefer the high-level APIs shown in this guide when writing notebooks or examples.

User guide

• Overview
  • Design principles
• Installation
  • Install from PyPI
  • Install from source
  • Remote Jupyter notebook Docker image
  • Docker tensor-network interpreter
• Typical workflow
  • Build a model
  • Build the constrained Hamiltonian
  • Builder choices
  • Inspect sectors
  • Search for cages
  • Classify a cage
  • Visualize
  • Open-system construction
• Thermodynamic ETH diagnostics
  • Match one local witness across sizes
  • Evaluate cage and thermal expectations
  • Factorized multi-block certification
  • Square-QDM strip transfer matrix
  • Winding-resolved periodic contractions
  • Evaluate a common cage witness family
  • Normalize and evaluate the actual cage-derived witness
  • Exact arbitrary-repeat cage sequences
  • Match the cage energy density to beta zero
  • Bi-periodic product-tile certification
  • Direct finite-tile search
  • Singlet-product stripes and the tensor-network handoff
• Tensor-network cage ansatzes
  • Rectangular vertex tensor
  • Quimb networks
  • Compact Autograd optimization
  • Visualization
  • Type-1 chiral specialization
  • Native chiral PEPS
  • Seam-resolved type-1 diagnostics
  • Targeted enlarged unit cells
• Minimal examples
  • Square QDM Hamiltonian
  • Square QLM with staggered background charges
  • Plaquette-dependent couplings and Peierls phases
  • Reuse a basis across builders
  • Cage search and first record
  • Reduced density matrix readout
  • Open-system time evolution
• Current development status
  • Stable or mostly stable
  • Active research layers
  • Planned documentation work
  • Backward-compatibility expectations
• Repository refactor status
  • Current decomposition
  • Removal gates
• Architecture diagnostics
  • Interactive report
  • Local diagnosis
  • CI and architecture enforcement

API reference

• qlinks package
  • Subpackages
  • Submodules
  • Module contents

Project

• Contributing