Emergent Phenomena in Multicomponent Quantum Condensates.

Quantum effects usually only matter at the microscopic scale. However, in superconductors and superfluids these quantum effects appear on a macroscopic level, leading to surprising properties such as frictionless or lossless flow. The macroscopic quantum state arises from the collective behavior of a large number of microscopic particles (Bose-Einstein condensation). In the case of fermionic particles these must first pair up. Neutral particles lead to superfluidity, charged ones to superconductivity. Both cases are described by the same underlying mathematical formalism.The discovery of superfluidity in magnesium diboride in 2001 marked the appearance of a new class of macroscopic quantum systems, the so-called multiband systems. They are characterized by multiple types of pairs, leading to a mixture of quantum condensates. This mixing of different types of quantum fluids within the confines of a single fluid or solid leads to a rich set of novel phenomena. Experimentally not only multiband superconductors have been realized but also multiband superfluids.The goal of the project is to study the interplay between these multiple quantum condensates and to quantify the effects of mixing. We aim to develop and extend the mathematical formalism to the multiband case, and to develop efficient solvers for the non-linear field equations characteristic for this formalism. This will be applied to study a wide range of macroscopic quantum phenomena, both for multiband superfluids and for multiband superconductors.

Keywords:SUPERFLUIDITY, NON-LINEAR SOLVERS, MULTIBAND PHYSICS, SUPERCONDUCTIVITY

Disciplines:Applied mathematics in specific fields, Astronomy and space sciences, Classical physics, Condensed matter physics and nanophysics, Materials physics, Mathematical physics, Quantum physics