Probing novel phases of matter with artificial quantum simulators: the interplay between disorder and
correlations in equilibrium and out-of-equilibrium many-body quantum lattices

FIRB 2012_RBFR12NLNA_003 ArtiQuS

Funded by: Ministero dell’Istruzione, Università e Ricerca (MIUR)  
Calls: FIRB
Start date: 2013-03-20  End date: 2016-03-20
Total Budget: EUR 861.089,00  INO share of the total budget: EUR 336.562,00
Scientific manager: Rossini Davide   and for INO is: D’Errico Chiara

Organization/Institution/Company main assignee: Scuola Normale Superiore di Pisa

other Organization/Institution/Company involved:

other INO’s people involved:

Modugno Giovanni

Abstract: ArtiQuS (ARTIficial QUantum Simulators) targets the realization of artificial structures properly tailored to reproduce controlled strongly correlated quantum systems, in order to explore the role of disorder and the dynamics. We will interface advanced theoretical methods with two different setups: ultracold atomic gases trapped in optical lattices and nanofabricated semiconductor quantum wells, with the aim to create a unique and interdisciplinary network merging young physicists who will make a fundamental step forward in the field of quantum simulations. In the specific, we plan to build up artificial lattice structures on which interacting quantum particles (bosonic particles with cold atoms, or fermionic particles with electrons in semiconductor structures) are able to tunnel from site to site. The different energy scales, interaction nature and quantum statistics involved in the two systems will allow to understand in depth the many-body physics of low 1 dimensional lattice systems.
In particular we will address two frontier themes in many-body quantum physics: the role played by disorder and the out-of-equilibrium dynamics of closed systems.
– Perfectly ordered systems do not exist in nature, and even weak perturbations of an ideal state can strongly modify the properties of a physical system. We aim at a complete characterization of the ground-state static properties of disordered Hubbard-like models, for bosons and fermions, both for short- and long-range interactions, including the emerging and subtle glassy phases. We will also tackle the challenging problem of the phase-diagram modifications induced by a finite temperature. Finally we will study the stability of topological quantum phases in presence of disorder. The potentialities offered by our two setups are immense: on one hand, with cold atoms we have the possibility to accurately control the disorder; on the other hand, we can artificially insert impurities in the semiconductor nanostructured lattice, where electron entanglement occurs via long-range Coulomb interactions.
– The out-of-equilibrium dynamics of closed many-body systems is a long and debated problem, starting from the dawn of quantum mechanics. In the last few years, renewed interest came from some spectacular experiments performed with optical lattices, which proved to be ideal candidates to address this issue. One of the most interesting questions concerns the thermalization of a many-body system following an abrupt quantum quench of one of the Hamiltonian parameters. The presence or absence of disorder could play a major role in dictating the long-time relaxation behavior. On the other side, the formation of defects after adiabatically crossing a quantum phase transition also covers a primary role in understanding and controlling such devices, and could be also crucial for adiabatic quantum computation schemes. New preparation and measurement techniques that we plan to operate in our setups, together with the further development of advanced numerical and analytical quantum many-body techniques, will eventually allow us to approach a complete insight of the above mentioned and debated issues.

INO’s Experiments/Theoretical Study correlated:
Novel phases of matter with artificial quantum simulators: disorder and correlations in equilibrium and out-of-equilibrium many-body quantum lattices

The Scientific Results:
1) Observation of a disordered bosonic insulator from weak to strong interactions