Novel surface universality classes with strong anisotropy

TL;DR

This paper introduces two new universality classes for anisotropic surface growth driven by oblique particle beams, analyzed through renormalized field theory revealing complex phase transitions and critical behavior.

Contribution

It identifies and characterizes two novel universality classes of surface fluctuations under anisotropic conditions using renormalization group analysis.

Findings

Discovery of two new universality classes for anisotropic surface growth.

Identification of a phase diagram with continuous and first-order transition lines.

Detailed scaling behavior at multicritical points.

Abstract

Using renormalized field theory, we examine the dynamics of a growing surface, driven by an obliquely incident particle beam. Its projection on the reference (substrate) plane selects a ``parallel'' direction, so that the evolution equation for the surface height becomes anisotropic. The phase diagram of the model is controlled by the properties of an effective anisotropic surface tension. Our renormalization group analysis suggests the existence of a line of continuous transitions and a line of (potentially) first-order transitions, which meet at a multicritical point. The full scaling behavior for the continuous line and the multicritical point is discussed in detail. Two novel universality classes for scale-invariant surface fluctuations are found.