About QUINST

Quantum mechanics is at the heart of our technology and economy - the laser and the transistor are quantum devices - but its full potential is far from being realized. Recent technological advances in optics, nanoscience and engineering allow experimentalists to create artificial structures or put microscopic and mesoscopic systems under new manipulable conditions in which quantum phenomena play a fundamental role.

Quantum technologies exploit these effects with practical purposes. The objective of Quantum Science is to discover, study, and control quantum efects at a fundamental level. These are two sides of a virtuous circle: new technologies lead to the discovery and study of new phenomena that will lead to new technologies.

Our group's aim is  to control and understand quantum phenomena in a multidisciplinary intersection of  Quantum Information, Quantum optics and cold atoms, Quantum Control, Spintronics, Quantum metrology, Atom interferometry, Superconducting qubits and Circuit QED and Foundations of Quantum Mechanics.

 

 

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Miguel A. Cazalilla, Centro de Fisica de Materiales (Seminar)

When end where

11/2010

Description

2009/07/01, Miguel A. Cazalilla, Centro de Fisica de Materiales

Place: Salón de Grados, FCT-ZTF
Time: 12h.
Title: Quantum Simulation of the Hubbard model with Ultracold Atoms: The Attractive Route
Abstract
We study the conditions under which the phases sought after for the repulsive Hubbard model, namely a Mott insulator in the paramagnetic, and anti-ferromagnet, and a putative d-wave superfluid can be deduced from observations in an optical lattice loaded with a spin polarized ultra-cold Fermi gas with attractive interactions. Such a system thus realizes the attractive Hubbard model with spin imbalance. We show that, in the attractive Hubbard model and related by a well-known canonical transformation, the Mott insulator and antiferromagnetic phase of the repulsive Hubbard model are in fact easier to observe as a paired and superfluid phase, respectively. The putative d-wave superfluid phase of the repulsive Hubbard model doped away from half-filling is related to a d-wave antiferromagnetic phase for the attractive Hubbard model. We discuss the advantages of this approach to 'quantum simulate' the Hubbard model in an optical lattice over the approach that attempts to directly simulate the doped Hubbard model in the repulsive regime. We also point out a number of technical difficulties of the proposed approach and, in some cases, suggest possible solutions.