Non-Abelian Thouless pumping in a Rice–Mele ladder

Non-Abelian Thouless pumping intertwines adiabatic quantum control and topological quantum transport, and it holds potential for quantum metrology and computing. In this work, we introduce a ladder model featuring two doubly degenerate bands and we show that adiabatic manipulation of the lattice parameters results in non-Abelian Thouless pumping, inducing both the displacement of an initially localized state and a geometric unitary transformation within the degenerate subspace. Additionally, we show that the structure and symmetry of the ladder model can be understood through its connection to a Yang monopole model. The proposed Hamiltonian can be realized using cold atoms in optical lattices, enabling the experimental demonstration of non-Abelian Thouless pumping in a genuinely quantum many-body system.