Are Vortex Quasi-Crystals New Phases of Vortex Matter?

TL;DR

This paper proposes the existence of vortex quasi-crystals as a new phase of vortex matter in superconductors, stabilized by quasi-periodic potentials or boundary effects, with phase transitions influenced by sample size, magnetic field, and temperature.

Contribution

It introduces the concept of vortex quasi-crystals, extending the phase diagram of vortex matter to include quasi-crystalline phases influenced by sample geometry and external conditions.

Findings

Vortex quasi-crystals can be stabilized by quasi-periodic potentials.

Boundary and surface effects influence vortex phase stability.

Phase transitions between vortex crystal and quasi-crystal depend on sample size, magnetic field, and temperature.

Abstract

There seems to be a one to one correspondence between the phases of atomic and molecular matter (AMOM) and vortex matter (VM) in superfluids and superconductors. Crystals, liquids and glasses have been experimentally observed in both AMOM and VM. However, quasi-crystals also exist in AMOM, thus a new phase of vortex matter is proposed here: the vortex quasi-crystal. It is argued that vortex quasi-crystals are stabilized due to imposed quasi-periodic potentials in large samples or due to boundary and surface energy effects for samples of special shapes and sizes. For finite size samples, it is proposed that a phase transition between a vortex crystal and a vortex quasi-crystal occurs as a function of magnetic field and temperature as the sample size is reduced.