Quasi-local Edge Mode in XXX Spin Chain/Circuit with Interaction Boundary Defect (opens in new tab)

arXiv:2603.17835v1 Announce Type: cross Abstract: We study the Heisenberg spin-1/2 model on a semi-infinite chain - or, equivalently, a trotterized unitary SU(2) symmetric six-vertex quantum circuit - with a boundary defect where the interaction between the two spins nearest the edge differs from that in the bulk. For sufficiently strong boundary interaction we explicitly construct a conserved operator quasi-localized near the boundary using a matrix-product ansatz. This quasi-local edge mod...