Topological edge state transfer via topological adiabatic passage

Abstract

The study of quantum state transfer has led to a variety of research efforts utilizing quantum simulators. By exploiting the tunability of the qubit frequency and qubit-qubit coupling, a superconducting qubit chain can simulate various topological band models. In our study, we demonstrate that a spin-up state can be transported along a topological qubit chain by modulating the coupling strengths and the qubit frequencies. We show that the Hilbert space of the qubit chain can be restricted to the subspace of two edge states in this process, while the Hamiltonian degenerates into a two-state Landau-Zener (LZ) model. Furthermore, we prove that the state transfer process in this topological qubit chain is equivalent to the topological adiabatic passage of the LZ model. With this analysis, we generalize the state transfer approach from single-qubit Fock states to two-qubit Bell states.