Seminario Pietro Massignan

Strong-coupling Ansatz for 1D quantum mixtures in a harmonic potential

AVVISO DI SEMINARIO

                                                                                                                                                                                                              

 

DATA  Giovedì 11 Giugno 2015                                    ORE 15:00

 

RELATORE:  Pietro Massignan

 

ISTITUTO DI APPARTENENZA: ICFO, Barcelona (Spain)

 

TITOLO DEL SEMINARIO  Strong-coupling Ansatz for 1D quantum mixtures in a harmonic potential

AULA : Querzoli LENS

 

ABSTRACT

Quantum systems in one dimension are often exactly solvable, even in presence of strong interactions.

However, no general solution is known for bosons or fermions in a trap.

Here, we propose a novel Ansatz for generating the lowest-energy wavefunctions of the repulsive 1D Fermi gas in a harmonic potential near the Tonks-Girardeau limit of infinite interactions.

Focusing on a single impurity interacting with N identical fermions, we show that the overlap between all wavefunctions from our Ansatz and the exact ones in the ground-state manifold exceeds 0.999 for N<=8, and remains at this level of precision even when extrapolating to the thermodynamic limit. Since our Ansatz states may be obtained combinatorially, all wavefunctions in the ground state of a system with N~100 can be calculated in a matter of seconds on a standard laptop. We employ this Ansatz to compute numerous ground state properties such as the contact, the residue, the tunneling probability, and the energy shifts of states in higher manifolds. We finally discuss how this Ansatz can be generalized to the study of general quantum mixtures, in view of realizing a variety of strongly-interacting magnetic phases.

 

Referente: Matteo Zaccanti

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