The Fulde–Ferrell–Larkin–Ovchinnikov State in Quantum Rings

Abstract

The Fulde–Ferrell–Larkin–Ovchinnikov (FFLO) state is a super-conducting phase with oscillating order parameter in real space. It is an effect of broken translation symmetry of the system. Similarly, for the quantum rings, an angular FFLO phase comes into existence and breaks the rotation symmetry. We are pondering possible realizations of non-trivial FFLO in superconducting quantum rings. To find distribution of the order parameter in real space, we use the Bogoliubov–de Gennes equations. On the basis of numerical results, we analyse distribution of the order parameter for different quantum rings as a function of their geometrical sizes.