Self-masking of spontaneous symmetry breaking in layer materials

TL;DR

This paper investigates d-wave Fermi surface deformations in bilayer and layered square lattices, revealing a self-masking spontaneous symmetry breaking phenomenon that depends on interlayer coupling and stacking patterns.

Contribution

It demonstrates that the (+,-) stacking pattern is generally favored in layered materials with finite c axis dispersion, leading to self-masked symmetry breaking.

Findings

(+,-) stacking is usually favored with finite c axis dispersion

Self-masking of spontaneous symmetry breaking occurs in layer materials

No macroscopic anisotropy arises despite symmetry breaking

Abstract

We study d-wave Fermi surface deformations (dFSD), the so-called Pomeranchuk instability, on bilayer and infinite-layer square lattices. Since the order parameter of the dFSD has Ising symmetry, there are two stacking patterns along the c axis: (+,+) and (+,-). We find that, as long as the c axis dispersion is finite at the saddle points of the in-plane band dispersion, the (+,-) stacking is usually favored independently on the details of interlayer coupling, yielding no macroscopic anisotropy. The dFSD provides unique spontaneous symmetry breaking that is self-masked in layer materials.