Ara es mostren els items 1-17 de 17

  • 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)
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    Accés obert
    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 ...
  • Dynamic structure function of a cold Fermi gas at unitarity 

    Astrakharchik, Grigori; Boronat Medico, Jordi; Krotscheck, Eckhard; Lichtenegger, Thomas (Institute of Physics (IOP), 2014-08-14)
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    We present a theoretical study of the dynamic structure function of a resonantly interacting two-component Fermi gas at zero temperature. Our approach is based on dynamic many-body theory able to describe excitations in ...
  • Exact ground-state properties of a one-dimensional Coulomb gas 

    Astrakharchik, Grigori; Girardeau, M.D. (2011-04-15)
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    Accés obert
    The ground-state properties of a single-component one-dimensional Coulomb gas are investigated. We use Bose-Fermi mapping for the ground-state wave function which permits solution of the Fermi sign problem in the following ...
  • Low-dimensional weakly interacting Bose gases: nonuniversal equations of state 

    Astrakharchik, Grigori; Boronat Medico, Jordi; Kurbakov, I L; Lozovik, Y E; Mazzanti Castrillejo, Fernando Pablo (2010-01)
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    The zero-temperature equation of state is analyzed in low-dimensional bosonic systems. We propose to use the concept of energy-dependent s-wave scattering length for obtaining estimations of nonuniversal terms in the energy ...
  • Luttinger-liquid behavior of one-dimensional He-3 

    Astrakharchik, Grigori; Boronat Medico, Jordi (2014-12-30)
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    The ground-state properties of one-dimensional He-3 are studied using quantum Monte Carlo methods. The equation of state is calculated in a wide range of physically relevant densities and is well interpolated by a power-series ...
  • One dimensional H-1, H-2 and H-3 

    Vidal, A.J.; Astrakharchik, Grigori; Vranješ Markic, Leandra; Boronat, J. (2016-05-26)
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    Accés obert
    The ground-state properties of one-dimensional electron-spin-polarized hydrogen H-1, deuterium H-2, and tritium 3 Hare obtained by means of quantum Monte Carlo methods. The equations of state of the three isotopes are ...
  • One-dimensional Bose gas in optical lattices of arbitrary strength 

    Astrakharchik, Grigori; Krutitsky, K.V.; Lewenstein, Maciej; Mazzanti Castrillejo, Fernando Pablo (2016-02-08)
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    Accés obert
    One-dimensional Bose gas with contact interaction in optical lattices at zero temperature is investigated by means of the exact diffusion Monte Carlo algorithm. The results obtained from the fundamental continuous model ...
  • One-dimensional multicomponent Fermi gas in a trap: quantum Monte Carlo study 

    Matveeva, N.; Astrakharchik, Grigori (2016-06-22)
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    Accés obert
    A one-dimensional world is very unusual as there is an interplay between quantum statistics and geometry, and a strong short-range repulsion between atoms mimics Fermi exclusion principle, fermionizing the system. Instead, ...
  • Phase diagram of a quantum Coulomb wire 

    Ferré Porta, Guillem; Astrakharchik, Grigori; Boronat Medico, Jordi (2015-12-09)
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  • 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)
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    Accés obert
    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, ...
  • Quantum phase transition with a simple variational ansatz 

    Lutsyshyn, Yaroslav; Astrakharchik, Grigori; Cazorla, C; Boronat Medico, Jordi (2014-12-11)
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    We study the zero-temperature quantum phase transition between liquid and hcp solid He-4. We use the variational method with a simple yet exchange-symmetric and fully explicit wave function. It is found that the optimized ...
  • Quantum versus mean-field collapse in a many-body system 

    Astrakharchik, Grigori; Malomed, Boris A. (2015-10-29)
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    The recent analysis, based on the mean-field approximation (MFA), has predicted that the critical quantum collapse of the bosonic wave function, pulled to the center by the inverse-square potential in the three-dimensional ...
  • Reentrant behavior of the breathing-mode-oscillation frequency in a one-dimensional Bose gas 

    Gudyma, A; Astrakharchik, Grigori; Zvonarev, Mikhail (2015-08-07)
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    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 ...
  • Sharp crossover from composite fermionization to phase separation in microscopic mixtures of ultracold bosons 

    Garcia March, Miguel Angel; Julia Diaz, Bruno; Astrakharchik, Grigori; Busch, T; Boronat Medico, Jordi; Rios Polls, Artur (2013-12-03)
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    Accés obert
    We show that a two-component mixture of a few repulsively interacting ultracold atoms in a one-dimensional trap possesses very diverse quantum regimes and that the crossover between them can be induced by tuning the ...
  • 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)
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    Accés obert
    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 ...
  • Ultradilute low-dimensional liquids 

    Petrov, D. S.; Astrakharchik, Grigori (2016-09-01)
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    Accés obert
    We calculate the energy of one- and two-dimensional weakly interacting Bose-Bose mixtures analytically in the Bogoliubov approximation and by using the diffusion Monte Carlo technique. We show that in the case of attractive ...
  • Zero-temperature phase diagram of Yukawa bosons 

    Osychenko, O.N.; Astrakharchik, Grigori; Mazzanti Castrillejo, Fernando Pablo; Boronat Medico, Jordi (2012)
    Article
    Accés obert
    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 ...