Modern potentials and the properties of condensed<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">He</mml:mi></mml:mrow><mml:mprescripts /><mml:mrow /><mml:mrow><mml:mn>4</mml:mn></mml:mrow><mml:mrow /><mml:mrow /></mml:mmultiscripts></mml:mrow></mml:math>

Kalos, M. H.; Lee, Michael A.; Whitlock, Paula A.; Chester, G. V.

doi:10.1103/physrevb.24.115

Cited by 266 publications

(148 citation statements)

References 36 publications

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“…The PIGS method provides estimates of ground-state properties and imaginary-time correlations functions, which are only affected by two errors: (i) the use of a finite imaginary time of projection in (8), and (ii) the use of a finite time step in (9). The biases introduced by these approximations can be reduced below the statistical uncertainties of the calculation by taking τ sufficiently large and δτ sufficiently small [43].…”

Section: The Pigs Methodsmentioning

confidence: 99%

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Roton Excitations and the Fluid–Solid Phase Transition in Superfluid 2D Yukawa Bosons

et al. 2016

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We compute several groundstate properties and the dynamical structure factor of a 0-temperature system of Bosons interacting with the 2D screened Coulomb (2D-SC) potential. We resort to the exact shadow path-integral ground-state (SPIGS) quantum Monte Carlo method to compute the imaginary-time correlation function of the model, and to the genetic algorithm via falsification of theories (GIFT) to retrieve the dynamical structure factor. We provide a detailed comparison of groundstate properties and collective excitations of 2D-SC and 4 He atoms. The roton energy of the 2D-SC system is an increasing function of density, and not a decreasing one as in 4 He. This result is in contrast with the view that the roton is the soft mode of the fluid-solid transition. We uncover a remarkable quasi-universality of backflow and of other properties when expressed in terms of the amount of short range order as quantified by the height of the first peak of the static structure factor.

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Section: The Pigs Methodsmentioning

confidence: 99%

“…The He-He interaction is characterized by a hard repulsive core at short distance and by a rather weak attraction at larger distances, as typified by the Lennard-Jones form. In fact, it is well-established that most properties of such system are determined by the hard core, the attractive tail playing a minor role [8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Roton Excitations and the Fluid–Solid Phase Transition in Superfluid 2D Yukawa Bosons

et al. 2016

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“…While the variational treatment is used for quantum phase transitions at the mean-field level [14], it is relatively uncommon that a (discontinuous) transition can be described with a microscopic wave function. The finding is also interesting in light of growing interest to the first-order quantum phase transitions [15,16].At zero temperature, the phases of 4 He can be studied in an essentially exact form with a family of projector methods, including Green's-function Monte Carlo [17,18] [23,24], and describe the transition [25][26][27] and coexistence [28] between the two phases. The SWFs can be seen as representing a single step of a projection calculation [23].…”

mentioning

confidence: 99%

“…At zero temperature, the phases of 4 He can be studied in an essentially exact form with a family of projector methods, including Green's-function Monte Carlo [17,18], diffusion Monte Carlo [19], and path-integral ground-state Monte Carlo [20]. These methods properly describe the phase transition in helium, and can provide insight on the nature of its ground state [21,22].…”

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confidence: 99%

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Quantum phase transition with a simple variational ansatz

et al. 2014

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We study the zero-temperature quantum phase transition between liquid and hcp solid 4 He. We use the variational method with a simple yet exchange-symmetric and fully explicit wave function. It is found that the optimized wave function undergoes spontaneous symmetry breaking and describes the quantum solidification of helium at 22 atm. The explicit form of the wave function allows us to consider various contributions to the phase transition. We find that the employed wave function is an excellent candidate for describing both a first-order quantum phase transition and the ground state of a Bose solid. Properties of solid 4 He have regained attention due to a host of unexpected physics discovered in the past decade [1][2][3][4][5][6][7][8]. Most of the new features occur close to absolute zero and are believed to be primarily driven by quantum effects. Consequently, the solidification of 4 He came under renewed scrutiny. The role of quantum statistics in the transition location has been recently revisited in Ref. [9]. At small but nonzero temperatures, indistinguishability of particles destabilizes the quantum solid. Distinguishable particles, on the other hand, would solidify even at low pressures, with the phase diagram reminiscent of the Pomeranchuk effect [10,11]. The feature was dubbed in [9] as thermocrystallization. A similar effect was seen numerically for the Wigner-crystallization of a two-dimensional Coulomb system [12]. The solidification of 4 He at zero temperature was revisited in Ref. [13] with the density functional theory (DFT). Results were improved compared with previous DFT studies.In this paper, we show that the quantum solidification of 4 He can be considered variationally, with a single explicit wave-function which selects the phase through optimization of the thermodynamic potential. Quite surprisingly, we find that the phase transition is predicted properly, given the relative simplicity of the wave function. While the variational treatment is used for quantum phase transitions at the mean-field level [14], it is relatively uncommon that a (discontinuous) transition can be described with a microscopic wave function. The finding is also interesting in light of growing interest to the first-order quantum phase transitions [15,16].At zero temperature, the phases of 4 He can be studied in an essentially exact form with a family of projector methods, including Green's-function Monte Carlo [17,18] [23,24], and describe the transition [25][26][27] and coexistence [28] between the two phases. The SWFs can be seen as representing a single step of a projection calculation [23]. The projection is carried out by performing the numerical integration of the shadow degrees of freedom. In this sense, the SWF is not fully explicit, as one cannot write down the result of such an integration. We consider SWF calculations as a class of their own, in between the exact projection methods and the simple and fully explicit wave function used here.Highly effective wave functions have been developed over the years...

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Quantum Monte Carlo Simulations of Solid 4He

Whitlock

Vitiello

2006

Large-Scale Scientific Computing

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Modern potentials and the properties of condensedHe4

Cited by 266 publications

References 36 publications

Roton Excitations and the Fluid–Solid Phase Transition in Superfluid 2D Yukawa Bosons

Roton Excitations and the Fluid–Solid Phase Transition in Superfluid 2D Yukawa Bosons

Quantum phase transition with a simple variational ansatz

Quantum Monte Carlo Simulations of Solid 4He

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