G. Bertaina

First and second sound in cylindrically trapped gases.

We investigate the propagation of density and temperature waves in a cylindrically trapped gas with radial harmonic confinement. Starting from two-fluid hydrodynamic theory we derive effective 1D equations for the chemical potential and the temperature which explicitly account for the effects of viscosity and thermal conductivity. Differently from quantum fluids confined by rigid walls, the harmonic confinement allows for the propagation of both first and second sound in the long wavelength limit. We provide quantitative predictions for the two sound velocities of a superfluid Fermi gas at unitarity. For shorter wavelengths we discover a new surprising class of excitations continuously spread over a finite interval of frequencies. This results in a nondissipative damping in the response function which is analytically calculated in the limiting case of a classical ideal gas.

Quantum Monte Carlo Study of a Resonant Bose-Fermi Mixture

We study a resonant Bose-Fermi mixture at zero temperature by using the fixed-node diffusion Monte Carlo method. We explore the system from weak to strong boson-fermion interaction, for different concentrations of the bosons relative to the fermion component. We focus on the case where the boson density n(B) is smaller than the fermion density n(F), for which a first-order quantum phase transition is found from a state with condensed bosons immersed in a Fermi sea, to a Fermi-Fermi mixture of composite fermions and unpaired fermions. We obtain the equation of state and the phase diagram, and we find that the region of phase separation shrinks to zero for vanishing n(B).

Dynamical structure factor of one-dimensional hard rods

The zero-temperature dynamical structure factor

Statistical and computational intelligence approach to analytic continuation in Quantum Monte Carlo

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Two-dimensional short-range interacting attractive and repulsive Fermi gases at zero temperature

of one-dimensional hard rods is computed using state-of-the-art quantum Monte Carlo and analytic continuation techniques, complemented by a Bethe ansatz analysis. As the density increases,

Condensed phase of Bose-Fermi mixtures with a pairing interaction

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Implementation of the Linear Method for the optimization of Jastrow-Feenberg and Backflow Correlations

reveals a crossover from the Tonks-Girardeau gas to a quasisolid regime, along which the low-energy properties are found in agreement with the nonlinear Luttinger liquid theory. Our quantitative estimate of

Density profiles of polarized Fermi gases confined in harmonic traps

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Linear Response of One-Dimensional Liquid ^4\hbox {He} to External Perturbations

extends beyond the low-energy limit and confirms a theoretical prediction regarding the behavior of

Microscopic Study of Static and Dynamical Properties of Dilute One-Dimensional Soft Bosons

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