Sample-based Krylov quantum diagonalization of a two-orbital impurity model

The two-orbital impurity model captures essential multi-orbital correlation effects beyond the single-orbital impurity limit. Here we study a two-orbital impurity model using the sample-based Krylov quantum diagonalization (SKQD) method. To estimate the ground-state energy efficiently, we apply SKQD on IBM Quantum hardware to sample a Krylov subspace and process the measurements classically. With this approach, we compare the resulting energies with exact diagonalization and find good agreement. These results demonstrate the potential of SKQD as a scalable quantum solver for strongly correlated electron models.