Quantum wetting transition in the one-dimensional transverse-field Ising model with random bonds

The quantum wetting transition in the one-dimensional transverse-field Ising model with random bonds is studied. Opposite boundary fields are applied at the two ends of the Ising chain. The interface between two domains with oppositely oriented magnetization is localized near the boundary or in the middle of the chain. The wetting transition refers to the phase transition of localization and delocalization of the interface. The tuning parameter h(L) is the boundary field at one end, e.g., the left end. At the transition point h(L )= h(w) the wetting transition occurs. First, we study the wetting transition with one defect bond. It is a first-order transition, and the interface jumps from the left end of the chain to the defect bond at the transition point. Second, we study the wetting transition with two defect bonds and find that the weaker defect bond dominates the phase transition. The wetting transition is still first order, and the interface is localized at the left end of the chain or at the weaker defect bond. Lastly, the random bond case is studied. The random bonds have a rectangular distribution. The wetting transition is still first order. The finite-size effects are studied. The statistics of the transition points and the energy gaps are obtained. We study lattices with sizes N = 100, 150, 200, 250, 300, and 350. The deviation of the phase transition points h(w) does not decrease as the lattice size increases. It is argued that the transition point is sample dependent, i.e., the variation in the transition point h(w) does not approach zero, even at the thermodynamic limit.