Speaker
Description
Recent advances have introduced deterministic quantum algorithms capable of preparing Bethe states, providing a unitary realization of the Bethe Ansatz. We systematize these developments by demonstrating that such circuits naturally arise from a well-established structure in quantum integrable models: the F-basis. We hope that this approach can help to characterize the computational complexity of preparing integrable eigenstates. In this sense, the Bethe circuits have proven to match the efficiency of previous state of the art algorithms for free fermions. In a related development, we demonstrate that eigenstates of a selected class of interacting spin chains can be prepared using polynomial resources in system size and particle number. We consider an integrable rigid-rod deformation of the spin 1/2 XXZ model with simple interactions that exhibits Hilbert space fragmentation. Realistic error-mitigated noisy simulations of the associated circuits with up to 13 qubits are performed, obtaining a promising relative error below 5%.
