Model wavefunctions for interfaces between lattice Laughlin states*

The interfaces between topological orders are predicted to display nontrivial phenomena, e.g., the anyonic Andreev reflection. However, for chiral topological orders (such as quantum Hall states), they are hard to study microscopically, because of the required system size and the lack of exactly solvable models.

In this work, we overcome this difficulty by using the conformal field theory to construct model wavefunctions for interfaces between two lattice Laughlin states at different fillings. Then, we study them using Monte Carlo methods, showing that they share many characteristics with gapped interfaces described earlier in the literature (restriction to certain filling factors, charge neutrality condition consistent with the gapping interaction, entanglement entropy scaling). However, the behavior of the correlation function suggests that they are in fact an another, gapless kind of interface.

We also consider localized quasiholes in the presence of interface, determining their density profile, charge and mutual statistics. We show that some of them lose their anyonic character after crossing the interface, leading to the same restrictions on the anyon motion as predicted for gapped interfaces.