papers

Publications (114)

cond-mat.soft2002

Dynamic structure factor of a Bose Einstein condensate in a 1D optical lattice

C. Menotti, M. Kraemer, L. Pitaevskii +1

We study the effect of a one dimensional periodic potential on the dynamic structure factor of an interacting Bose Einstein condensate at zero temperature. We show that, due to pho…

cond-mat.stat-mech2003

Kelvin Modes of a fast rotating Bose-Einstein Condensate

F. Chevy, S. Stringari

Using the concept of diffused vorticity and the formalism of rotational hydrodynamics we calculate the eigenmodes of a harmonically trapped Bose-Einstein condensate containing an a…

cond-mat.soft2008

Destroying superfluidity by rotating a Fermi gas at unitarity

I. Bausmerth, A. Recati, S. Stringari

We study the effect of the rotation on a harmonically trapped Fermi gas at zero temperature under the assumption that vortices are not formed. We show that at unitarity the rotatio…

cond-mat.quant-gas2018

Observation of Spin Superfluidity in a Bose Gas Mixture

E. Fava, T. Bienaimé, C. Mordini +5

The spin dynamics of a harmonically trapped Bose-Einstein condensed binary mixture of sodium atoms is experimentally investigated at finite temperature. In the collisional regime t…

cond-mat2000

Kinetic energy of a trapped Fermi gas interacting with a Bose-Einstein condensate

L. Vichi, M. Amoruso, A. Minguzzi +2

We study a confined mixture of bosons and fermions in the regime of quantal degeneracy, with particular attention to the effects of the interactions on the kinetic energy of the fe…

cond-mat1999

Interference of Bose-Einstein condensates in momentum space

L. Pitaevskii, S. Stringari

We suggest an experiment to investigate the linear superposition of two spatially separated Bose-Einstein condensates. Due to the coherent combination of the two wave functions, th…

physics.atom-ph2007

Measurement of the Temperature Dependence of the Casimir-Polder Force

J. M. Obrecht, R. J. Wild, M. Antezza +3

We report on the first measurement of a temperature dependence of the Casimir-Polder force. This measurement was obtained by positioning a nearly pure 87-Rb Bose-Einstein condensat…

cond-mat1999

Dynamic structure factor and momentum distribution of a trapped Bose gas

F. Zambelli, L. P. Pitaevskii, D. M. Stamper-Kurn +1

The dynamic structure factor of a trapped Bose-Einstein condensed gas is investigated at zero temperature in the framework of Bogoliubov theory. Different values of momentum transf…

cond-mat1994

Structural and dynamical properties of superfluid helium: a density functional approach

F. Dalfovo, A. Lastri, L. Pricaupenko +2

We present a novel density functional for liquid 4He, properly accounting for the static response function and the phonon-roton dispersion in the uniform liquid. The functional is…

cond-mat.stat-mech2004

Oscillations of a Bose-Einstein condensate rotating in a harmonic plus quartic trap

M. Cozzini, A. L. Fetter, B. Jackson +1

We study the normal modes of a two-dimensional rotating Bose-Einstein condensate confined in a quadratic plus quartic trap. Hydrodynamic theory and sum rules are used to derive ana…

cond-mat1996

Quantum Evaporation from the Free Surface of Superfluid 4He

F. Dalfovo, A. Fracchetti, A. Lastri +2

The scattering of atoms and rotons at the free surface of superfluid 4He is studied in the framework of linearised time dependent mean field theory. The phenomenological Orsay-Tren…

cond-mat.other2006

Collective mode of homogeneous superfluid Fermi gases in the BEC-BCS crossover

R. Combescot, M. Yu. Kagan, S. Stringari

We perform a detailed study of the collective mode across the whole BEC-BCS crossover in fermionic gases at zero temperature, covering the whole range of energy beyond the linear r…

cond-mat.quant-gas2018

Magnetic defects in an unbalanced mixture of two Bose-Einstein condensates

A. Gallemí, L. P. Pitaevskii, S. Stringari +1

When the spectrum of magnetic excitations of a quantum mixture is much softer than the density spectrum, the system becomes effectively incompressible and can host magnetic defects…

cond-mat1999

Collective oscillations of an interacting trapped Fermi gas

L. Vichi, S. Stringari

We calculate the effects of two-body interactions on the low frequency oscillations of a normal Fermi gas confined in a harmonic trap. The mean field contribution to the collective…

cond-mat1996

Quantum Evaporation from Superfluid Helium at Normal Incidence

F. Dalfovo, M. Guilleumas, A. Lastri +2

We study the scattering of atoms, rotons and phonons at the free surface of He at normal incidence and calculate the evaporation, condensation and reflection probabilities. Ass…

cond-mat.quant-gas2023

The cross-over from Townes solitons to droplets in a 2D Bose mixture

B. Bakkali-Hassani, C. Maury, S. Stringari +3

When two Bose-Einstein condensates -- labelled 1 and 2 -- overlap spatially, the equilibrium state of the system depends on the miscibility criterion for the two fluids. Here, we t…

cond-mat.soft2006

Spin polarizability of a trapped superfluid Fermi gas

A. Recati, I. Carusotto, C. Lobo +1

The polarization produced by the relative displacement of the potentials trapping two spin species of a dilute Fermi gas with $N_\ua=N_\da$ is calculated at unitarity by assuming p…

cond-mat1993

Dispersion Law of Edge Waves in the Quantum Hall Effect

S. Giovanazzi, L. Pitaevskii, S. Stringari

We present a microscopic description of edge excitations in the quantum Hall effect which is analogous to Feynman's theory of superfluids. Analytic expressions for the excitation e…

cond-mat.quant-gas2010

Second sound and the density response function in uniform superfluid atomic gases

H. Hu, E. Taylor, X. -J. Liu +2

Recently there has been renewed interest in second sound in superfluid Bose and Fermi gases. By using two-fluid hydrodynamic theory, we review the density response $χ_{nn}(\bq,ω)…

cond-mat.quant-gas2009

Critical velocity of superfluid flow through single barrier and periodic potentials

Gentaro Watanabe, F. Dalfovo, F. Piazza +2

We investigate the problem of an ultracold atomic gas in the superfluid phase flowing in the presence of a potential barrier or a periodic potential. We use a hydrodynamic scheme i…

cond-mat2000

Overcritical Rotation of a Trapped Bose-Einstein Condensate

A. Recati, F. Zambelli, S. Stringari

The rotational motion of an interacting Bose-Einstein condensate confined by a harmonic trap is investigated by solving the hydrodynamic equations of superfluids, with the irrotati…

cond-mat1996

Scaling and thermodynamics of a trapped Bose-condensed gas

S. Giorgini, L. Pitaevskii, S. Stringari

We investigate the thermodynamics of a Bose gas interacting with repulsive forces and confined in a harmonic trap. We show that the relevant parameters of the system (temperature,…

cond-mat1993

Spin Excitations and Sum Rules in the Heisenberg Antiferromagnet

S. Stringari

Various bounds for the energy of collective excitations in the Heisenberg antiferromagnet are presented and discussed using the formalism of sum rules. We show that the Feynman app…

cond-mat.quant-gas2020

Measurement of the Canonical Equation of State of a Weakly Interacting 3D Bose Gas

C. Mordini, D. Trypogeorgos, A. Farolfi +4

Using a multiple-image reconstruction method applied to a harmonically trapped Bose gas, we determine the equation of state of uniform matter across the critical transition point,…

cond-mat.other2005

Equation of state and collective frequencies of a trapped Fermi gas along the BEC-unitarity crossover

G. E. Astrakharchik, R. Combescot, X. Leyronas +1

We show that the study of the collective oscillations in a harmonic trap provides a very sensitive test of the equation of state of a Fermi gas near a Feshbach resonance. Using a s…

cond-mat.other2008

The role of interactions in spin-polarised atomic Fermi gases at unitarity

A. Recati, C. Lobo, S. Stringari

We study the zero temperature properties of a trapped polarized Fermi gas at unitarity by assuming phase separation between an unpolarized superfluid and a polarized normal phase.…

cond-mat.other2009

Chandrasekhar-Clogston limit and phase separation in Fermi mixtures at Unitarity

I. Bausmerth, A. Recati, S. Stringari

Using many-body results available from diagrammatic and {\it ab initio} Monte Carlo calculations we analyze the phase diagram versus $h=(μ_{…

cond-mat.quant-gas2012

Rapid ramps across the BEC-BCS crossover: a novel route to measuring the superfluid gap

R. G. Scott, F. Dalfovo, L. P. Pitaevskii +1

We investigate the response of superfluid Fermi gases to rapid changes of the three-dimensional s-wave scattering length a by solving the time-dependent Bogoliubov-de Gennes equati…

cond-mat.other2006

One-dimensional description of a Bose-Einstein condensate in a rotating closed-loop waveguide

S. Schwartz, M. Cozzini, C. Menotti +3

We propose a general procedure for reducing the three-dimensional Schrodinger equation for atoms moving along a strongly confining atomic waveguide to an effective one-dimensional…

cond-mat1995

Bosons in anisotropic traps: ground state and vortices

F. Dalfovo, S. Stringari

We solve the Gross-Pitaevskii equations for a dilute atomic gas in a magnetic trap, modeled by an anisotropic harmonic potential. We evaluate the wave function and the energy of th…

cond-mat.quant-gas2023

Superfluid fraction in an interacting spatially modulated Bose-Einstein condensate

G. Chauveau, C. Maury, F. Rabec +7

At zero temperature, a Galilean-invariant Bose fluid is expected to be fully superfluid. Here we investigate theoretically and experimentally the quenching of the superfluid densit…

cond-mat1998

Quantum degeneracy and interaction effects in spin-polarized Fermi-Bose mixtures

L. Vichi, M. Inguscio, S. Stringari +1

Various features of spin-polarized Fermi gases confined in harmonic traps are discussed, taking into account possible perspectives of experimental measurements. The mechanism of th…

cond-mat1997

Collective and single particle excitations of a trapped Bose gas

F. Dalfovo, S. Giorgini, M. Guilleumas +2

The density of states of a Bose-condensed gas confined in a harmonic trap is investigated. The predictions of Bogoliubov theory are compared with the ones of Hartree-Fock theory an…

cond-mat.soft2007

Equilibrium and dynamics of a trapped superfluid Fermi gas with unequal masses

G. Orso, L. P. Pitaevskii, S. Stringari

Interacting Fermi gases with equal populations but unequal masses are investigated at zero temperature using local density approximation and the hydrodynamic theory of superfluids…

cond-mat1992

Uncertainty Principle and Off-Diagonal Long Range Order in the Fractional Quantum Hall Effect

L. Pitaevskii, S. Stringari

A natural generalization of the Heisenberg uncertainty principle inequality holding for non hermitian operators is presented and applied to the fractional quantum Hall effect (FQHE…

cond-mat.quant-gas2019

Supersolid symmetry breaking from compressional oscillations in a dipolar quantum gas

L. Tanzi, S. M. Roccuzzo, E. Lucioni +6

The existence of a paradoxical supersolid phase of matter, possessing the apparently incompatible properties of crystalline order and superfluidity, was predicted 50 years ago. Sol…

cond-mat.quant-gas2019

Static-response theory and the roton-maxon spectrum of a flattened dipolar Bose-Einstein condensate

R. N. Bisset, P. B. Blakie, S. Stringari

Important information for the roton-maxon spectrum of a flattened dipolar Bose-Einstein condensate is extracted by applying a static perturbation exhibiting a periodic in-plane mod…

cond-mat.quant-gas2011

The decay and collisions of dark solitons in superfluid Fermi gases

R. G. Scott, F. Dalfovo, L. P. Pitaevskii +4

We study soliton collisions and the decay of solitons into sound in superfluid Fermi gases across the Bose-Einstein condensate to Bardeen-Cooper-Schrieffer (BEC-BCS) crossover by p…

cond-mat2000

Shape deformations and angular momentum transfer in trapped Bose-Einstein condensates

F. Dalfovo, S. Stringari

Angular momentum can be transferred to a trapped Bose-Einstein condensate by distorting its shape with an external rotating field, provided the rotational frequency is larger than…

cond-mat1996

Nonlinear Dynamics of a Bose Condensed Gas

F. Dalfovo, C. Minniti, S. Stringari +1

We investigate the dynamic behavior of a Bose-condensed gas of alkali atoms interacting with repulsive forces and confined in a magnetic trap at zero temperature. Using the Thomas-…

cond-mat1995

Moment of Inertia and Superfluidity of a Trapped Bose Gas

S. Stringari

The temperature dependence of the moment of inertia of a dilute Bose gas confined in a harmonic trap is determined. Deviations from the rigid value, due to the occurrence of Bose-E…

cond-mat.quant-gas2009

Entropy exchange in a mixture of ultracold atoms

J. Catani, G. Barontini, G. Lamporesi +5

We investigate experimentally the entropy transfer between two distinguishable atomic quantum gases at ultralow temperatures. Exploiting a species-selective trapping potential, we…

cond-mat2003

Momentum distribution of a trapped Fermi gas with large scattering length

L. Viverit, S. Giorgini, L. P. Pitaevskii +1

Using a scattering length parametrization of the BCS-BEC crossover as well as the local density approximation for the density profile, we calculate the momentum distribution of a h…

cond-mat.quant-gas2016

Minimally destructive, Doppler measurement of a quantized, superfluid flow

A. Kumar, N. Anderson, W. D. Phillips +3

The Doppler effect, the shift in the frequency of sound due to motion, is present in both classical gases and quantum superfluids. Here, we perform an in-situ, minimally destructiv…

cond-mat.stat-mech2008

Collisional Properties of a Polarized Fermi Gas with Resonant Interactions

G. M. Bruun, A. Recati, C. J. Pethick +2

Highly polarized mixtures of atomic Fermi gases constitute a novel Fermi liquid. We demonstrate how information on thermodynamic properties may be used to calculate quasiparticle s…

cond-mat1996

Order Parameter at the Boundary of a Trapped Bose Gas

F. Dalfovo, L. Pitaevskii, S. Stringari

Through a suitable expansion of the Gross-Pitaevskii equation near the classical turning point, we obtain an explicit solution for the order parameter at the boundary of a trapped…

cond-mat.soft2004

Umklapp collisions and center of mass oscillation of a trapped Fermi gas

G. Orso, L. P. Pitaevskii, S. Stringari

Starting from the the Boltzmann equation, we study the center of mass oscillation of a harmonically trapped normal Fermi gas in the presence of a one-dimensional periodic potential…

cond-mat.quant-gas2021

Supersolid edge and bulk phases of a dipolar quantum gas in a box

S. M. Roccuzzo, S. Stringari, Alessio Recati

We investigate the novel density distributions acquired by a dipolar Bose-Einstein condensed gas confined in a box potential, with special focus on the effects of supersolidity. Di…

cond-mat.quant-gas2020

Rotating a supersolid dipolar gas

S. M. Roccuzzo, A. Gallemí, A. Recati +1

Distintictive features of supersolids show up in their rotational properties. We calculate the moment of inertia of a harmonically trapped dipolar Bose-Einstein condensed gas as a…

cond-mat.stat-mech2008

Density and spin response function of a normal Fermi gas at unitarity

S. Stringari

Using Landau theory of Fermi liquids we calculate the dynamic response of both a polarized and unpolarized normal Fermi gas at zero temperature in the strongly interacting regime o…

cond-mat.quant-gas2011

Dipolar Drag in Bilayer Harmonically Trapped Gases

N. Matveeva, A. Recati, S. Stringari

We consider two separated pancake-shaped trapped gases interacting with a dipolar (either magnetic or electric) force. We study how the center of mass motion propagates from one cl…

cond-mat.soft2001

Consequence of superfluidity on the expansion of a rotating Bose-Einstein condensate

Mark Edwards, Charles W. Clark, P. Pedri +2

We study the time evolution of a rotating condensate, that expands after being suddenly released from the confining trap, by solving the hydrodynamic equations of irrotational supe…

cond-mat1995

Bounds for the phonon-roton dispersion in superfluid 4He

J. Boronat, J. Casulleras, F. Dalfovo +2

The sum rule approach is used to derive upper bounds for the dispersion law of the elementary excitations of a Bose superfluid. Bounds are explicitly calculated for the p…

cond-mat1992

Static Response Function for Longitudinal and Transverse Excitations in Superfluid Helium

F. Dalfovo, S. Stringari

The sum rule formalism is used to evaluate rigorous bounds for the density and current static response functions in superfluid helium at zero temperature. Both lower and upper boun…

cond-mat.soft2001

Expansion of a coherent array of Bose-Einstein condensates

P. Pedri, L. Pitaevskii, S. Stringari +6

We investigate the properties of a coherent array containing about 200 Bose-Einstein condensates produced in a far detuned 1D optical lattice. The density profile of the gas, image…

cond-mat.other2006

Quantum fluctuations and collective oscillations of a Bose-Einstein condensate in a 2D optical lattice

G. Orso, C. Menotti, S. Stringari

We use Bogoliubov theory to calculate the beyond mean field correction to the equation of state of a weakly interacting Bose gas in the presence of a tight 2D optical lattice. We s…

cond-mat1998

Theory of Bose-Einstein condensation in trapped gases

F. Dalfovo, S. Giorgini, L. P. Pitaevskii +1

The phenomenon of Bose-Einstein condensation of dilute gases in traps is reviewed from a theoretical perspective. Mean-field theory provides a framework to understand the main feat…

cond-mat1998

Dynamics of Bose condensed gases in highly deformed traps

S. Stringari

We provide a unified investigation of normal modes and sound propagation at zero temperature in Bose condensed gases confined in highly asymmetric harmonic traps and interacting wi…

cond-mat.quant-gas2014

Counter-flow instability of a quantum mixture of two superfluids

M. Abad, A. Recati, S. Stringari +1

We study the instability of a mixture of two interacting counter-flowing superfluids. For a homogeneous system, we show that superfluid hydrodynamics leads to the existence of a dy…

cond-mat2001

A superfluid gyroscope with cold atomic gases

S. Stringari

A trapped Bose-Einstein condensed atomic gas containing a quantized vortex is predicted to exhibit precession after a sudden rotation of the confining potential. The equations desc…

cond-mat.quant-gas2009

First and second sound in a strongly interacting Fermi gas

E. Taylor, H. Hu, X. -J. Liu +3

Using a variational approach, we solve the equations of two-fluid hydrodynamics for a uniform and trapped Fermi gas at unitarity. In the uniform case, we find that the first and se…

cond-mat1993

Sum Rules and Bose-Einstein Condensation

S. Stringari

Various sum rules accounting for the coupling between density and particle excitations and emphasizing in an explicit way the role of the Bose-Einstein condensation are discussed.…

cond-mat.quant-gas2012

Increasing Quantum Degeneracy by Heating a Superfluid

D. J. Papoular, G. Ferrari, L. P. Pitaevskii +1

We consider a uniform superfluid confined in two compartments connected by a superleak and initially held at equal temperatures. If one of the two compartments is heated, a fractio…

cond-mat.soft2004

Propagation of sound in a Bose Einstein condensate in an optical lattice

C. Menotti, M. Kramer, A. Smerzi +2

We study the propagation of sound waves in a Bose-Einstein condensate trapped in a one-dimensional optical lattice. We find that the velocity of propagation of sound wavepackets de…

cond-mat1995

Density functional calculations for 4He droplets

M. Casas, F. Dalfovo, A. Lastri +2

A novel density functional, which accounts correctly for the equation of state, the static response function and the phonon-roton dispersion in bulk liquid helium, is used to predi…

cond-mat2000

How to measure the Bogoliubov quasiparticle amplitudes in a trapped condensate

A. Brunello, F. Dalfovo, L. Pitaevskii +1

We propose an experiment, based on two consecutive Bragg pulses, to measure the momentum distribution of quasiparticle excitations in a trapped Bose gas at low temperature. With th…

cond-mat1996

The Surface Region of Superfluid He as a Dilute Bose-Condensed Gas

A. Griffin, S. Stringari

In the low-density surface region of superfluid He, the atoms are far apart and collisions can be ignored. The only effect of the interactions is from the long-range attractive…

cond-mat.soft1999

Scissors mode and superfluidity of a trapped Bose-Einstein condensed gas

D. Guery-Odelin, S. Stringari

We investigate the oscillation of a dilute atomic gas generated by a sudden rotation of the confining trap (scissors mode). This oscillation reveals the effects of superfluidity ex…

cond-mat.soft2005

Sound propagation and oscillations of a superfluid Fermi gas in the presence of a 1D optical lattice

L. P. Pitaevskii, S. Stringari, G. Orso

We develop the hydrodynamic theory of Fermi superfluids in the presence of a periodic potential. The relevant parameters governing the propagation of sound (compressibility and eff…

cond-mat1998

Dynamical response of a Bose-Einstein condensate to a discontinuous change in internal state

M. R. Matthews, D. S. Hall, D. S. Jin +6

A two-photon transition is used to convert an arbitrary fraction of the 87Rb atoms in a |F=1,m_f=-1> condensate to the |F=2,m_f=1> state. Transferring the entire population imposes…

cond-mat2003

Dynamics of a classical gas including dissipative and mean field effects

P. Pedri, D. Guéry-Odelin, S. Stringari

By means of a scaling ansatz, we investigate an approximated solution of the Boltzmann-Vlasov equation for a classical gas. Within this framework, we derive the frequencies and the…

cond-mat.quant-gas2014

Fast thermalization and Helmholtz oscillations of an ultracold Bose gas

D. J. Papoular, L. P. Pitaevskii, S. Stringari

We analyze theoretically the transport properties of a weakly-interacting ultracold Bose gas enclosed in two reservoirs connected by a constriction. We assume that the transport of…

cond-mat.quant-gas2016

Quantized conductance through the quantum evaporation of bosonic atoms

D. J. Papoular, L. P. Pitaevskii, S. Stringari

We analyze theoretically the quantization of conductance occurring with cold bosonic atoms trapped in two reservoirs connected by a constriction with an attractive gate potential.…

cond-mat.quant-gas2021

Moment of Inertia and Dynamical Rotational Response of a Supersolid Dipolar Gas

S. M. Roccuzzo, A. Recati, S. Stringari

We show that the knowledge of the time dependent response of a trapped gas, subject to a sudden rotation of a confining harmonic potential, allows for the determination of the mome…

cond-mat2003

Violation of self-similarity in the expansion of a 1D Bose gas

P. Pedri, L. Santos, P. Ohberg +1

The expansion of a 1D Bose gas is investigated employing the Lieb-Liniger equation of state within the local density approximation. We show that during the expansion the density pr…

cond-mat2001

Thermal vs quantum decoherence in double well trapped Bose-Einstein condensates

L. Pitaevskii, S. Stringari

The quantum and thermal fluctuations of the phase are investigated in a cold Bose gas confined by a double well trap. The coherence of the system is discussed in terms of the visib…

cond-mat1996

Collective excitations of a trapped Bose-condensed gas

S. Stringari

By taking the hydrodynamic limit we derive, at , an explicit solution of the linearized time dependent Gross-Pitaevskii equation for the order parameter of a Bose gas confined…

cond-mat.other2008

Unitary polarized Fermi gas under adiabatic rotation

I. Bausmerth, A. Recati, S. Stringari

We discuss the effect of an adiabatic rotation on the phase separation between the superfluid and normal component of a trapped polarized Fermi gas at unitarity and zero temperatur…

cond-mat.other2005

Molecular signatures in the structure factor of an interacting Fermi gas

R. Combescot, S. Giorgini, S. Stringari

The static and dynamic structure factors of an interacting Fermi gas along the BCS-BEC crossover are calculated at momentum transfer higher than the Fermi momentum.…

cond-mat1995

Rotons and Quantum Evaporation from Superfluid 4He

F. Dalfovo, A. Fracchetti, A. Lastri +2

The probability of evaporation induced by and rotons at the surface of superfluid helium is calculated using time dependent density functional theory. We consider excit…

cond-mat1997

Anomalous fluctuations of the condensate in interacting Bose gases

S. Giorgini, L. P. Pitaevskii, S. Stringari

We find that the fluctuations of the condensate in a weakly interacting Bose gas confined in a box of volume follow the law . This anomalous behaviour ar…

cond-mat.quant-gas2011

Local atom-number fluctuations in quantum gases at finite temperature

M. Klawunn, A. Recati, L. P. Pitaevskii +1

We investigate the number fluctuations in small cells of quantum gases pointing out important deviations from the thermodynamic limit fixed by the isothermal compressibility. Both…

cond-mat.mes-hall2005

Vortex lattices in Bose-Einstein condensates: from the Thomas-Fermi to the lowest Landau level regime

M. Cozzini, S. Stringari, C. Tozzo

We consider a periodic vortex lattice in a rotating Bose-Einstein condensed gas, where the centrifugal potential is exactly compensated by the external harmonic trap. By introducin…

cond-mat.stat-mech2004

Collisions and expansion of an ultracold dilute Fermi gas

B. Jackson, P. Pedri, S. Stringari

We discuss the effects of collisions on the expansion of a degenerate normal Fermi gas, following the sudden removal of the confining trap. Using a Boltzmann equation approach, we…

cond-mat2001

Vortex nucleation and quadrupole deformation of a rotating Bose-Einstein condensate

M. Kraemer, L. Pitaevskii, S. Stringari +1

Using a semi-analytic model based on the Thomas-Fermi approximation, we investigate the relevance of the quadrupole deformation of a trapped Bose-Einstein condensate for the nuclea…

cond-mat1996

Hydrodynamic modes in a trapped Bose gas above the Bose-Einstein transition

A. Griffin, Wen-Chin Wu, S. Stringari

We discuss the collective modes of a trapped Bose gas in the hydrodynamic regime where atomic collisions ensure local thermal equilibrium for the distribution function. Starting fr…

cond-mat1994

Dispersion of Ripplons in Superfluid 4he

A. Lastri, F. Dalfovo, L. Pitaevskii +1

A detailed study of the dispersion law of surface excitations in liquid \hef at zero temperature is presented, with special emphasis to the short wave length region. The hybridizat…

cond-mat.quant-gas2010

First and second sound in cylindrically trapped gases

G. Bertaina, L. Pitaevskii, S. Stringari

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 deri…

cond-mat2001

Momentum transferred to a trapped Bose-Einstein condensate by stimulated light scattering

A. Brunello, F. Dalfovo, L. Pitaevskii +2

The response of a trapped Bose-Einstein condensed gas to a density perturbation generated by a two-photon Bragg pulse is investigated by solving the time-dependent Gross-Pitaevskii…

cond-mat1998

Elementary excitations in trapped Bose gases beyond mean field approximation

L. Pitaevskii, S. Stringari

Using hydrodynamic theory of superfluids and the Lee-Huang-Yang equation of state for interacting Bose gases we derive the first correction to the collective frequencies of a trapp…

cond-mat1994

Variational Calculations for He Impurities on He Droplets

A. Belić, F. Dalfovo, S. Fantoni +1

Variational Monte Carlo method is used to calculate ground state properties of He droplets, containing 70, 112, 168, 240, 330, and 728 particles. The resulting particle and kin…

cond-mat.soft2004

Insulating Behavior of a Trapped Ideal Fermi Gas

L. Pezze', L. Pitaevskii, A. Smerzi +7

We investigate theoretically and experimentally the center-of-mass motion of an ideal Fermi gas in a combined periodic and harmonic potential. We find a crossover from a conducting…

cond-mat2001

Helium nanodroplets and trapped Bose-Einstein condensates as prototypes of finite quantum fluids

F. Dalfovo, S. Stringari

Helium nanodroplets and trapped Bose-Einstein condensates in dilute atomic gases offer complementary views of fundamental aspects of quantum many-body systems. We discuss analogies…

cond-mat.quant-gas2021

Roadmap on Atomtronics: State of the art and perspective

L. Amico, M. Boshier, G. Birkl +56

Atomtronics deals with matter-wave circuits of ultra-cold atoms manipulated through magnetic or laser-generated guides with different shapes and intensities. In this way, new types…

cond-mat.other2006

Normal state of a polarized Fermi gas at unitarity

C. Lobo, A. Recati, S. Giorgini +1

We study the Fermi gas at unitarity and at T=0 by assuming that, at high polarizations, it is a normal Fermi liquid composed of weakly interacting quasiparticles associated with th…

cond-mat1997

Landau damping in dilute Bose gases

L. P. Pitaevskii, S. Stringari

Landau damping in weakly interacting Bose gases is investigated by means of perturbation theory. Our approach points out the crucial role played by Bose-Einstein condensation and y…

cond-mat.soft2002

Expansion of an interacting Fermi gas

C. Menotti, P. Pedri, S. Stringari

We study the expansion of a dilute ultracold sample of fermions initially trapped in a anisotropic harmonic trap. The expansion of the cloud provides valuable information about the…

cond-mat2002

Macroscopic dynamics of a trapped Bose-Einstein condensate in the presence of 1D and 2D optical lattices

M. Kraemer, L. Pitaevskii, S. Stringari

The hydrodynamic equations of superfluids for a weakly interacting Bose gas are generalized to include the effects of periodic optical potentials produced by stationary laser beams…

cond-mat1996

Condensate fraction and critical temperature of a trapped interacting Bose gas

S. Giorgini, L. Pitaevskii, S. Stringari

By using a mean field approach, based on the Popov approximation, we calculate the temperature dependence of the condensate fraction of an interacting Bose gas confined in an aniso…

cond-mat1998

Temperature-dependent density profiles of trapped boson-fermion mixtures

M. Amoruso, A. Minguzzi, S. Stringari +2

We present a semiclassical three-fluid model for a Bose-condensed mixture of interacting Bose and Fermi gases confined in harmonic traps at finite temperature. The model is used to…