Solvers¶

qkrylov includes several highly optimized solvers tailored for matrix-free quantum systems.

• Lanczos Algorithm: Best for finding the exact ground state and a few of the lowest excited states of large, sparse Hermitian matrices.
• Davidson Algorithm: Ideal when you need multiple eigenvalues/eigenvectors simultaneously, offering better convergence properties for clustered spectra.
• Spectral Functions & Dynamics: Tools to compute dynamical correlation functions, density of states (DOS), and spectral functions using continued fraction expansions.
• Finite Temperature Lanczos Method (FTLM): Evaluates thermal expectation values and finite-temperature dynamics without fully diagonalizing the Hamiltonian.