Inverse roughening transition in the staggered body-centered solid-on-solid model

The F model and inverse F model in a staggered electric field are examined by using transfer matrices and finite-size scaling. It is shown that such a field induces a Kosterlitz-Thouless transition in the inverse F model, corresponding to an ''inverse'' roughening transition in the body-centered solid-on-solid representation: a crystal facet appears above a certain temperature. It disappears again in the limit of infinite temperature. We find the location of this phase transition as a function of staggered field and for a specific choice of this field we estimate the facet size as a function of temperature.