Technology Blogs and Articles

Quantum Solver Achieves Efficient Solution of Single-Impurity Anderson Models with Particle-Hole Symmetry

Researchers from Middle Tennessee State University and Oak Ridge National Laboratory introduced a quantum‑classical hybrid solver that uses the variational quantum eigensolver (VQE) to tackle the Anderson impurity model (AIM) within dynamical mean‑field theory (DMFT). The solver employs a unified shallow‑circuit ansatz to prepare both ground‑state and particle‑hole excitations, enabling reconstruction of the impurity Green’s function via a continued‑fraction expansion. Benchmarking against classical pipelines across multiple bath sizes and interaction strengths shows accurate density‑of‑states (DOS) results and comparable or faster convergence, even under realistic noise and shot‑limited conditions. Optimization comparisons (COBYLA, Adam, L‑BFGS‑B) and a quantum‑computed moment correction further improve fidelity, establishing practical benchmarks for future DMFT integrations.