Final Report Summary - DISQUA (Disorder physics with ultracold quantum gases)
Disorder is ubiquitous in nature, but a clear understanding of its role in the behaviour of quantum systems is still missing. The idea of DISQUA is to employ ultracold quantum gases to explore various open problems in the physics of disorder, such as Anderson localization, or the interplay of disorder and interactions, which could not be solved so far from studies on real and engineered materials, or even in theory. Here we combine the full tunability of Bose and Fermi quantum gases (temperature, density, interaction, dimensionality) with controlled disorder created with optical potentials.
An important result we have obtained so far is the first characterization of the low-temperature phase diagram of disordered 1D bosons, the paradigmatic problem that has been investigated in theory since 25 years, with yet no clear observation. In particular, we have observed how disorder and interactions concur to determine the peculiar equilibrium and transport properties, and we have observed a predicted Bose glass phase, a counterintuitive gapless insulator that arises in the regime of strong correlations.
Another outstanding result is the first direct measurement of the mobility edge for Anderson localization in three dimensions, i.e the critical energy for localization. This has been an open problem in physics for several decades, and many other attempts based on different physical systems had so far failed.
These key systems, as well other types of quantum systems we have explored in DISQUA are allowing to investigate outstanding open questions that have foundational aspects but are also related to the behaviour of real materials, such as disordered metals and superconductors, or even biological systems.
An important result we have obtained so far is the first characterization of the low-temperature phase diagram of disordered 1D bosons, the paradigmatic problem that has been investigated in theory since 25 years, with yet no clear observation. In particular, we have observed how disorder and interactions concur to determine the peculiar equilibrium and transport properties, and we have observed a predicted Bose glass phase, a counterintuitive gapless insulator that arises in the regime of strong correlations.
Another outstanding result is the first direct measurement of the mobility edge for Anderson localization in three dimensions, i.e the critical energy for localization. This has been an open problem in physics for several decades, and many other attempts based on different physical systems had so far failed.
These key systems, as well other types of quantum systems we have explored in DISQUA are allowing to investigate outstanding open questions that have foundational aspects but are also related to the behaviour of real materials, such as disordered metals and superconductors, or even biological systems.