scholarly journals Beyond Lee-Huang-Yang description of self-bound Bose mixtures

2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Miki Ota ◽  
Gregory Astrakharchik
Keyword(s):  
Monte Carlo ◽  
Excellent Agreement ◽  
Quantum Monte Carlo ◽  
Mean Field ◽  
Finite Size ◽  
Pitaevskii Equation ◽  
Phonon Modes ◽  
Type Interaction ◽  
The Stability ◽  
The One

We investigate the properties of self-bound ultradilute Bose-Bose mixtures, beyond the Lee-Huang-Yang description. Our approach is based on the determination of the beyond mean-field corrections to the phonon modes of the mixture in a self-consistent way and calculation of the associated equation of state. The newly obtained ground state energies show excellent agreement with recent quantum Monte Carlo calculations, providing a simple and accurate description of the self-bound mixtures with contact type interaction. We further show numerical results for the equilibrium properties of the finite size droplet, by adjusting the Gross-Pitaevskii equation. Our analysis is extended to the one-dimensional mixtures where an excellent agreement with quantum Monte Carlo predictions is found for the equilibrium densities. Finally, we discuss the effects of temperature on the stability of the liquid phase.

MONTE CARLO STUDY OF ONE HOLE IN A QUANTUM ANTIFERROMAGNET

1992 ◽  
Vol 06 (05n06) ◽  
pp. 587-588
Author(s):  
S. Sorella
Keyword(s):  
Magnetic Field ◽  
Monte Carlo ◽  
Thermodynamic Limit ◽  
Quantum Monte Carlo ◽  
Finite Size ◽  
Monte Carlo Study ◽  
Mott Insulator ◽  
Trial Wavefunction ◽  
The One ◽  
Quantum Antiferromagnet

Using the standard Quantum Monte Carlo technique for the Hubbard model, I present here a numerical investigation of the hole propagation in a Quantum Antiferromagnet. The calculation is very well stabilized, using selected sized systems and special use of the trial wavefunction that satisfy the “close shell condition” in presence of an arbitrarily weak Zeeman magnetic field, vanishing in the thermodynamic limit. It will be shown in a forthcoming publication1 that the presence of this magnetic field does not affect thermodynamic properties for the half filled system. Then I have used the same selected sizes for the one hole ground state. I have investigated the question of vanishing or nonvanishing quasiparticle weight, in order to clarify whether the Mott insulator should behave just as conventional insulator with an upper and lower Hubbard band. By comparing the present finite size scaling with several techniques predicting a finite quasiparticle weight (see Fig.1) the data seem more consistent with a vanishing quasiparticle weight, i.e. , as recently suggested by P.W. Anderson2 the Hubbard-Mott insulator should be characterized by non-trivial excitations which cannot be interpreted in a simple quasi-particle picture. However it cannot be excluded , based only on numerical grounds, that a very small but non vanishing quasiparticle weight should survive in the thermodynamic limit.

scholarly journals Controlling ion transport through nanopores: modeling transistor behavior

2018 ◽  
Vol 20 (37) ◽  
pp. 24156-24167 ◽  
Author(s):  
Eszter Mádai ◽  
Bartłomiej Matejczyk ◽  
András Dallos ◽  
Mónika Valiskó ◽  
Dezső Boda
Keyword(s):  
Monte Carlo ◽  
Ion Transport ◽  
Hybrid Method ◽  
Local Equilibrium ◽  
Mean Field ◽  
Finite Size ◽  
Continuum Theory ◽  
Particle Simulation ◽  
Modeling Study

We present a modeling study of a nanopore-based transistor computed by a mean-field continuum theory (Poisson–Nernst–Planck, PNP) and a hybrid method including particle simulation (Local Equilibrium Monte Carlo, LEMC) that is able to take ionic correlations into account including the finite size of ions.

scholarly journals Unconventional phase transitions in strongly anisotropic 2D (pseudo)spin systems

2018 ◽  
Vol 185 ◽  
pp. 08006
Author(s):  
Vitaly Konev ◽  
Evgeny Vasinovich ◽  
Vasily Ulitko ◽  
Yury Panov ◽  
Alexander Moskvin
Keyword(s):  
Magnetic Field ◽  
Monte Carlo ◽  
Phase Transitions ◽  
Ground State ◽  
Quantum Monte Carlo ◽  
Mean Field ◽  
Spin Systems ◽  
Field Approach ◽  
Generalized Mean

We have applied a generalized mean-field approach and quantum Monte-Carlo technique for the model 2D S = 1 (pseudo)spin system to find the ground state phase with its evolution under application of the (pseudo)magnetic field. The comparison of the two methods allows us to clearly demonstrate the role of quantum effects. Special attention is given to the role played by an effective single-ion anisotropy ("on-site correlation").

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