Role of anomalous symmetry in 0-$\pi$ qubits

TL;DR

This paper analyzes the symmetry properties of 0-$\

Contribution

It provides an exact symmetry analysis of 0-$\

Findings

Identifies points with enhanced anomalous symmetry in control space.

Shows robustness of ground state degeneracy due to symmetry.

Suggests potential for robust qubit design.

Abstract

We present an exact full symmetry analysis of the 0-$\pi$ superconducting circuit. We identify points in control parameter space of enhanced anomalous symmetry, which imposes robust twofold degeneracy of its ground state, that is for all values of the energy parameters of the model. We show, both analytically and numerically, how this anomalous symmetry is maintained in the low-energy sector, thus providing us with a strong candidate for robust qubit engineering.