Now showing items 1-18 of 18

    • Beyond-Luttinger-liquid thermodynamics of a one-dimensional Bose gas with repulsive contact interactions 

      Rosi, Giulia de; Massignan, Pietro Alberto; Lewenstein, Maciej; Astrakharchik, Grigori (American Physical Society, 2019-11-07)
      Article
      Open Access
      We present a thorough study of the thermodynamics of a one-dimensional repulsive Bose gas, focusing in particular on corrections beyond the Luttinger-liquid description. We compute the chemical potential, pressure, and ...
    • Bose-Bose mixtures at finite temperature 

      Pascual López, Gerard (Universitat Politècnica de Catalunya, 2019-06-25)
      Bachelor thesis
      Restricted access - author's decision
    • Composite boson description of a low-density gas of excitons 

      Golomedov, A. E.; Lozovik, Yu. E.; Astrakharchik, Grigori; Boronat Medico, Jordi (2017-10-13)
      Article
      Open Access
      Ground-state properties of a fermionic Coulomb gas are calculated using the fixed-node diffusion Monte Carlo method. The validity of the composite boson description is tested for different densities. We extract the ...
    • Diffusion Monte Carlo methods for spin-orbit-coupled ultracold Bose gases 

      Sánchez Baena, Juan; Boronat Medico, Jordi; Mazzanti Castrillejo, Fernando Pablo (American Physical Society (APS), 2018-11-27)
      Article
      Open Access
      We present two diffusion Monte Carlo (DMC) algorithms for systems of ultracold quantum gases featuring synthetic spin-orbit interactions. The first one is a spin-integrated DMC method which provides fixed-phase energy ...
    • Dipolar Bose Supersolid Stripes 

      Bombín Escudero, Raul; Boronat Medico, Jordi; Mazzanti Castrillejo, Fernando Pablo (2017-12-20)
      Article
      Open Access
      We study the superfluid properties of a system of fully polarized dipolar bosons moving in the XY plane. We focus on the general case where the polarization field forms an arbitrary angle a with respect to the Z axis, ...
    • Distinguishability, degeneracy, and correlations in three harmonically trapped bosons in one dimension 

      Garcia March, Miguel Angel; Julia Diaz, Bruno; Astrakharchik, Grigori; Boronat Medico, Jordi; Polls, A. (2014-12-01)
      Article
      Open Access
      We study a system of two bosons of one species and a third atom of a second species in a one-dimensional parabolic trap at zero temperature. We assume contact repulsive inter- and intraspecies interactions. By means of an ...
    • Droplets of trapped quantum dipolar bosons 

      Macia Rey, Adrián; Sánchez Baena, Juan; Boronat Medico, Jordi; Mazzanti Castrillejo, Fernando Pablo (2016-11-10)
      Article
      Open Access
      Strongly interacting systems of dipolar bosons in three dimensions confined by harmonic traps are analyzed using the exact path integral ground-state Monte Carlo method. By adding a repulsive two-body potential, we find a ...
    • Effects of Fermion Exchange on the Polarization of Exciton Condensates 

      Combescot, Monique; Combescot, Roland; Alloing, Mathieu; Dubin, François (APS Physics, 2015-03-04)
      Article
      Open Access
      Exchange interaction is responsible for the stability of elementary boson condensates with respect to momentum fragmentation. This remains true for composite bosons when single fermion exchanges are included but spin ...
    • Few-body bound states of two-dimensional bosons 

      Guijarro Gámez, Grecia; Astrakharchik, Grigori; Boronat Medico, Jordi; Bazak, Betzalel; Petrov, D. S. (American Physical Society (APS), 2020-04-07)
      Article
      Open Access
      We study clusters of the type $A_NB_M$ with N=M=3 in a two-dimensional mixture of A and B bosons, with attractive AB and equally repulsive AA and BB interactions. In order to check universal aspects of the problem, we ...
    • Gapped spectrum in pair-superfluid bosons 

      Astrakharchik, Grigori; Zillich, Robert E.; Mazzanti Castrillejo, Fernando Pablo; Boronat Medico, Jordi (2016-12-22)
      Article
      Open Access
      We study the ground state of a bilayer system of dipolar bosons with dipoles oriented by an external field perpendicularly to the two parallel planes. By decreasing the interlayer distance, for a fixed value of the strength ...
    • One dimensional quantum gases: from few to many 

      Amorós Binefa, Júlia (Universitat Politècnica de Catalunya, 2016-07-07)
      Bachelor thesis
      Open Access
      Covenantee:   Università degli studi di Trento
      The main objective of this project is to find the binding energy of an impurity interacting with a one-dimensional bosonic system of increasing size for different coupling strengths g. Both the bosons as well as the impurity ...
    • One-dimensional three-boson problem with two- and three-body interactions 

      Guijarro Gámez, Grecia; Pricoupenko, A.; Astrakharchik, Grigori; Boronat Medico, Jordi; Petrov, D. S. (American Physical Society (APS), 2018-06-14)
      Article
      Open Access
      We solve the three-boson problem with contact two- and three-body interactions in one dimension and analytically calculate the ground and excited trimer-state energies. Then, by using the diffusion Monte Carlo technique, ...
    • Phase diagram of dipolar bosons in two dimensions with tilted polarization 

      Macia Rey, Adrián; Boronat Medico, Jordi; Mazzanti Castrillejo, Fernando Pablo (2014-12-01)
      Article
      Open Access
      We analyze the ground state of a system of dipolar bosons moving in the XY plane and such that their dipolar moments are all aligned in a fixed direction in space. We focus on the general case where the polarization field ...
    • Quantum correlations and spatial localization in one-dimensional ultracold bosonic mixtures 

      Garcia March, Miguel Angel; Julia Diaz, Bruno; Astrakharchik, Grigori; Busch, Th; Boronat Medico, Jordi; Polls, A. (2014-10-07)
      Article
      Open Access
      We present the complete phase diagram for one-dimensional binary mixtures of bosonic ultracold atomic gases in a harmonic trap. We obtain exact results with direct numerical diagonalization for a small number of atoms, ...
    • Reentrant behavior of the breathing-mode-oscillation frequency in a one-dimensional Bose gas 

      Gudyma, A; Astrakharchik, Grigori; Zvonarev, Mikhail (2015-08-07)
      Article
      Open Access
      Exciting temporal oscillations of the density distribution is a high-precision method for probing ultracold trapped atomic gases. Interaction effects in their many-body dynamics are particularly puzzling and counter-intuitive ...
    • Single-particle versus pair superfluidity in a bilayer system of dipolar bosons 

      Macia Rey, Adrián; Astrakharchik, Grigori; Mazzanti Castrillejo, Fernando Pablo; Giorgini, Stefano; Boronat Medico, Jordi (2014-10-21)
      Article
      Open Access
      We consider the ground state of a bilayer system of dipolar bosons, where dipoles are oriented by an external field in the direction perpendicular to the parallel planes. Quantum Monte Carlo methods are used to calculate ...
    • Vortex macroscopic superpositions in ultracold bosons in a double-well potential 

      Garcia-March, M. A.; Carr, Lincoln D. (2015-03-23)
      Article
      Open Access
      We study macroscopic superpositions in the orbital rather than the spatial degrees of freedom, in a three-dimensional double-well system. We show that the ensuing dynamics of N interacting excited ultracold bosons, which ...
    • Zero-temperature phase diagram of Yukawa bosons 

      Osychenko, O.N.; Astrakharchik, Grigori; Mazzanti Castrillejo, Fernando Pablo; Boronat Medico, Jordi (2012)
      Article
      Open Access
      We study the zero-temperature phase diagram of bosons interacting via screened Coulomb (Yukawa) potential by means of the diffusion Monte Carlo method. The Yukawa potential is used as a model interaction in the neutron ...