Chiral Bloch-Zener oscillations of spin-orbit coupled cold atoms in an optical superlattice

We study the Bloch oscillation (BO) dynamics of spin-orbit coupled cold atoms in a one-dimensional Su-Schrieffer-Heeger optical lattice. The Hamiltonian of our system can be mapped into a tilted SSH ladder pierced by an effective magnetic flux. Based on the calculation of Wannier-Stark states, we investigate dynamical properties of BOs with the chiral character of spin-momentum locking. Importantly, the chiral Bloch-Zener oscillations can be induced by adjusting system parameters. The corresponding Landau-Zener (LZ) tunneling probability is analytically derived by the LZ model and we found a good agreement with the numerical simulation.