Topological Behavior of Pair Density Waves on a Kondo-Heisenberg Ladder

The pair density wave (PDW) phase, characterized by an oscillating superconductor order parameter, was proposed as part of the rich phase diagram of certain high temperature superconductors such as LBCO. One model exhibiting this phase in 1D is the Kondo-Heisenberg model (KHM). Past work has predicted that the PDW phase is topological, hosting protected edge modes. Using the density matrix renormalization group (DMRG), we explicitly illustrate the topological properties of the PDW phase of the KHM on finite systems. In particular, we show the emergence spin ½ edge states within the PDW phase.