### Abstract

Language | English |
---|---|

Number of pages | 13 |

Journal | Physical Review E |

Volume | 80 |

Issue number | 6 |

DOIs | |

Publication status | Published - 8 Dec 2009 |

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### Keywords

- electrostatics
- free energy
- perturbation theory
- plasma fluctuations
- plasma interactions
- plasma simulation
- plasma thermodynamics
- variational techniques

### Cite this

*Physical Review E*,

*80*(6). https://doi.org/10.1103/PhysRevE.80.061107

}

*Physical Review E*, vol. 80, no. 6. https://doi.org/10.1103/PhysRevE.80.061107

**One-component plasma of point charges and of charged rods.** / Hatlo, Marius M.; Karatrantos, Argyrios; Lue, Leo.

Research output: Contribution to journal › Article

TY - JOUR

T1 - One-component plasma of point charges and of charged rods

AU - Hatlo, Marius M.

AU - Karatrantos, Argyrios

AU - Lue, Leo

PY - 2009/12/8

Y1 - 2009/12/8

N2 - An approximate theory is developed to describe the properties of mobile particles with extended charge distributions in the presence of a neutralizing fixed background charge. Long-wavelength fluctuations of the electric potential are handled within a variational perturbation approximation, and the short-wavelength fluctuations are handled within a cumulant (fugacity) expansion. The distinct treatment of these two contributions to the free energy enables the theory to provide quantitative predictions for the properties of these systems from the weak- to the strong-coupling regimes. With this theory, we study three different variations in the classical one-component plasma model: a plasma of point charges, a plasma of particles consisting of 8 linearly bonded point charges (8-mer), and a plasma of line charges. The theory was found to agree well with the available computer simulation data for the electrostatic interaction energy of these systems for all values of the plasma coupling parameter examined (Gamma=0 to 400). In addition, we find that both the 8-mer rod and the line charge systems form a strongly ordered nematic phase, which is entirely driven by electrostatic interactions. The nematic phase only exists within a finite range of lengths of the charged particles. If the particles are too short or too long, the nematic phase does not appear. Finally, we find that the nematic phase is stable over a broader range of conditions for the line charge system than for the 8-mer rod system; consequently, the phase behavior of the one-component plasma is sensitive to the manner in which the charge is distributed on the particles.

AB - An approximate theory is developed to describe the properties of mobile particles with extended charge distributions in the presence of a neutralizing fixed background charge. Long-wavelength fluctuations of the electric potential are handled within a variational perturbation approximation, and the short-wavelength fluctuations are handled within a cumulant (fugacity) expansion. The distinct treatment of these two contributions to the free energy enables the theory to provide quantitative predictions for the properties of these systems from the weak- to the strong-coupling regimes. With this theory, we study three different variations in the classical one-component plasma model: a plasma of point charges, a plasma of particles consisting of 8 linearly bonded point charges (8-mer), and a plasma of line charges. The theory was found to agree well with the available computer simulation data for the electrostatic interaction energy of these systems for all values of the plasma coupling parameter examined (Gamma=0 to 400). In addition, we find that both the 8-mer rod and the line charge systems form a strongly ordered nematic phase, which is entirely driven by electrostatic interactions. The nematic phase only exists within a finite range of lengths of the charged particles. If the particles are too short or too long, the nematic phase does not appear. Finally, we find that the nematic phase is stable over a broader range of conditions for the line charge system than for the 8-mer rod system; consequently, the phase behavior of the one-component plasma is sensitive to the manner in which the charge is distributed on the particles.

KW - electrostatics

KW - free energy

KW - perturbation theory

KW - plasma fluctuations

KW - plasma interactions

KW - plasma simulation

KW - plasma thermodynamics

KW - variational techniques

U2 - 10.1103/PhysRevE.80.061107

DO - 10.1103/PhysRevE.80.061107

M3 - Article

VL - 80

JO - Physical Review E

T2 - Physical Review E

JF - Physical Review E

SN - 1539-3755

IS - 6

ER -