Ara es mostren els items 22-41 de 58

    • Liquid state of one-dimensional Bose mixtures: a quantum Monte Carlo study 

      Parisi, L.; Astrakharchik, Grigori; Giorgini, Stefano (American Institute of Physics (AIP), 2019-03-14)
      Article
      Accés obert
      By using exact quantum Monte Carlo methods we calculate the ground-state properties of the liquid phase in one-dimensional Bose mixtures with contact interactions. We find that the liquid state can be formed if the ratio ...
    • 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)
      Article
      Accés obert
      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)
      Article
      Accés obert
      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 ...
    • Many-body bound states and induced interactions of charged impurities in a bosonic bath 

      Astrakharchik, Grigori; Peña Ardila, Luis Aldemar; Jachymski, Krzysztof; Negretti, Antonio (2023-12-01)
      Article
      Accés obert
      Induced interactions and bound states of charge carriers immersed in a quantum medium are crucial for the investigation of quantum transport. Ultracold atom-ion systems can provide a convenient platform for studying this ...
    • Nucleation of helium in liquid lithium at 843 K and high pressures 

      Martí Rabassa, Jordi; Mazzanti Castrillejo, Fernando Pablo; Astrakharchik, Grigori; Batet Miracle, Lluís; Portos-Amill, Laura; Pedreño, Borja (Multidisciplinary Digital Publishing Institute (MDPI), 2022-04-13)
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      Accés obert
      Fusion energy stands out as a promising alternative for a future decarbonised energy system. In order to be sustainable, future fusion nuclear reactors will have to produce their own tritium. In the so-called breeding ...
    • One dimensional H-1, H-2 and H-3 

      Vidal, A.J.; Astrakharchik, Grigori; Vranješ Markic, Leandra; Boronat, J. (2016-05-26)
      Article
      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)
      Article
      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)
      Article
      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, ...
    • 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
      Accés obert
      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, ...
    • Optical lattices as a tool to study defect-induced superfluidity 

      Astrakharchik, Grigori; Krutitsky, K.V.; Lewenstein, Maciej; Mazzanti Castrillejo, Fernando Pablo; Boronat Medico, Jordi (AMER PHYSICAL SOC, 2017-09-05)
      Article
      Accés obert
      We study the superfluid response, the energetic and structural properties of a one-dimensional ultracold Bose gas in an optical lattice of arbitrary strength. We use the Bose-Fermi mapping in the limit of infinitely large ...
    • Phase diagram of a quantum Coulomb wire 

      Ferré Porta, Guillem; Astrakharchik, Grigori; Boronat Medico, Jordi (2015-12-09)
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      Accés obert
    • Phase diagram of quasi-two-dimensional bosons in a laser-speckle potential 

      Astrakharchik, Grigori; Krutitsky, K.V.; Navez, Patrick (2013-06)
      Article
      Accés obert
      We have studied the phase diagram of a quasi-two-dimensional interacting Bose gas at zero temperature in the presence of random potential created by laser speckles. The superfluid fraction and the fraction of particles ...
    • Polaron interactions and bipolarons in one-dimensional Bose bases in the strong coupling regime 

      Astrakharchik, Grigori (American Institute of Physics (AIP), 2021-09-03)
      Article
      Accés obert
      Bose polarons, quasiparticles composed of mobile impurities surrounded by cold Bose gas, can experience strong interactions mediated by the many-body environment and form bipolaron bound states. Here we present a detailed ...
    • 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
      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 halo states in two-dimensional dipolar clusters 

      Guijarro Gámez, Grecia; Astrakharchik, Grigori; Boronat Medico, Jordi (Nature, 2021-12-01)
      Article
      Accés obert
      A halo is an intrinsically quantum object defined as a bound state of a spatial size which extends deeply into the classically forbidden region. Previously, halos have been observed in bound states of two and less frequently ...
    • Quantum phase transition of a two-dimensional quadrupolar system 

      Astrakharchik, Grigori; Kurbakov, I. L.; Lozovik, Yu. E. (American Physical Society (APS), 2021-04-01)
      Article
      Accés obert
      Ensembles with long-range interactions between particles are promising for revealing strong quantum collective effects and many-body phenomena. Here we study the ground-state phase diagram of a two-dimensional Bose system ...
    • Quantum phase transition with a simple variational ansatz 

      Lutsyshyn, Yaroslav; Astrakharchik, Grigori; Cazorla, C; Boronat Medico, Jordi (2014-12-11)
      Article
      Accés obert
      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)
      Article
      Accés obert
      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)
      Article
      Accés obert
      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)
      Article
      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 ...