Browsing by Author "Astrakharchik, Grigori"

Quantum phase transition with a simple variational ansatz
Lutsyshyn, Yaroslav; Astrakharchik, Grigori; Cazorla, C; Boronat Medico, Jordi (20141211)
Article
Open AccessWe study the zerotemperature quantum phase transition between liquid and hcp solid He4. We use the variational method with a simple yet exchangesymmetric and fully explicit wave function. It is found that the optimized ... 
Quantum versus meanfield collapse in a manybody system
Astrakharchik, Grigori; Malomed, Boris A. (20151029)
Article
Open AccessThe recent analysis, based on the meanfield approximation (MFA), has predicted that the critical quantum collapse of the bosonic wave function, pulled to the center by the inversesquare potential in the threedimensional ... 
Reentrant behavior of the breathingmodeoscillation frequency in a onedimensional Bose gas
Gudyma, A; Astrakharchik, Grigori; Zvonarev, Mikhail (20150807)
Article
Open AccessExciting temporal oscillations of the density distribution is a highprecision method for probing ultracold trapped atomic gases. Interaction effects in their manybody dynamics are particularly puzzling and counterintuitive ... 
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 (20131203)
Article
Open AccessWe show that a twocomponent mixture of a few repulsively interacting ultracold atoms in a onedimensional trap possesses very diverse quantum regimes and that the crossover between them can be induced by tuning the ... 
Singleparticle versus pair superfluidity in a bilayer system of dipolar bosons
Macia Rey, Adrián; Astrakharchik, Grigori; Mazzanti Castrillejo, Fernando Pablo; Giorgini, Stefano; Boronat Medico, Jordi (20141021)
Article
Open AccessWe 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 ... 
Spin dynamics and AndreevBashkin effect in mixtures of onedimensional Bose gases
Parisi, L.; Astrakharchik, Grigori; Giorgini, Stefano (American Institute of Physics (AIP), 20180711)
Article
Open AccessWe investigate the propagation of spin waves in twocomponent mixtures of onedimensional Bose gases interacting through repulsive contact potentials. By using quantum Monte Carlo methods we calculate static groundstate ... 
The inversesquare interaction phase diagram: unitarity in the bosonic ground state
Astrakharchik, Grigori; Kryuchkov, P. S.; Kurbakov, I. L.; Lozovik, Yu. E. (Multidisciplinary Digital Publishing Institute (MDPI), 20180608)
Article
Open AccessGroundstate properties of bosons interacting via inverse square potential (three dimensional CalogeroSutherland model) are analyzed. A number of quantities scale with the density and can be naturally expressed in units ... 
Thermodynamic behavior of a onedimensional Bose gas at low temperature
de Rosi, Giulia; Astrakharchik, Grigori; Stringari, Sandro (AMER PHYSICAL SOC, 20170711)
Article
Open AccessWe show that the chemical potential of a onedimensional (1D) interacting Bose gas exhibits a nonmonotonic temperature dependence which is peculiar of superfluids. The effect is a direct consequence of the phononic nature ... 
Ultradilute lowdimensional liquids
Petrov, D. S.; Astrakharchik, Grigori (20160901)
Article
Open AccessWe calculate the energy of one and twodimensional weakly interacting BoseBose mixtures analytically in the Bogoliubov approximation and by using the diffusion Monte Carlo technique. We show that in the case of attractive ... 
Universality in ultradilute liquid BoseBose mixtures
Cikojevic, V.; Vranješ Markic, Leandra; Astrakharchik, Grigori; Boronat Medico, Jordi (American Physical Society (APS), 20190213)
Article
Open AccessWe have studied dilute BoseBose mixtures of atoms with attractive interspecies and repulsive intraspecies interactions using quantum Monte Carlo methods at T=0. Using a number of models for interactions, we determine the ... 
Zerotemperature phase diagram of Yukawa bosons
Osychenko, O.N.; Astrakharchik, Grigori; Mazzanti Castrillejo, Fernando Pablo; Boronat Medico, Jordi (2012)
Article
Open AccessWe study the zerotemperature 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 ...