  We study the quantum Ising chain with boundary dephasing. By doubling the
Hilbert space, the model is mapped to the Su-Schrieffer-Heeger model with
imaginary chemical potential at the edges. We show analytically and numerically
that the Liouvillian gap, i.e., the inverse relaxation time of the model,
scales with the system size $ N $ as $ N^{-3} $.
