402 research outputs found
Magnetized strongly coupled plasmas and how to realize them in a dusty plasma setup
Strongly coupled plasmas in which the interaction energy exceeds the kinetic
energy play an important role in many astrophysical and laboratory systems
including compact stars, laser plasmas and dusty plasmas. They exhibit many
unusual collective properties, such as liquid or crystalline behaviour,
peculiar oscillation spectra and transport properties. Recently, strongly
coupled plasmas were studied in the presence of a strong magnetic field by
computer simulations, and strong modifications of their transport properties
and oscillation spectra were observed. While strong magnetization is common in
stellar systems it is practically impossible to achieve in complex plasmas due
to the large mass of the dust particles. Here we discuss a recently
demonstrated approach to achieve very strong "magnetization" by a rotation of
the neutral gas, and we present new results for macroscopic two-dimensional
systems
Ground state of a confined Yukawa plasma
The ground state of an externally confined one-component Yukawa plasma is
derived analytically. In particular, the radial density profile is computed.
The results agree very well with computer simulations on three-dimensional
spherical Coulomb crystals. We conclude in presenting an exact equation for the
density distribution for a confinement potential of arbitrary geometry.Comment: 5 pages, 4 figure
Oscillation Spectrum of a Magnetized Strongly Coupled One-Component-Plasma
A first-principle study of the collective oscillation spectrum of a strongly
correlated one-component plasma in a strong magnetic field is presented. The
spectrum consists of six fundamental modes which are found to be in good
agreement with results from the Quasi-Localized Charge approximation. At high
frequencies additional modes are observed that include Bernstein-type
oscillations and their transverse counterparts which are of importance for the
high-frequency optical and transport properties of these plasmas
Fluid Modes of a Spherically Confined Yukawa Plasma
The normal modes of a three-dimensional Yukawa plasma in an isotropic,
harmonic confinement are investigated by solving the linearized cold fluid
equations. The eigenmodes are found analytically and expressed in terms of
hypergeometric functions. It is found that the mode frequencies solely depend
on the dimensionless plasma parameter , where is the plasma
radius and the inverse screening length. The eigenfrequencies increase
monotonically with and saturate in the limit . Compared
with the results in the Coulomb limit~[D. H. E. Dubin, Phys. Rev. Lett.
\textbf{66}, 2076 (1991)], we find a new class of modes characterized by the
number which determines the number of radial nodes in the perturbed
potential. These modes originate from the degenerate bulk modes of the Coulomb
system. Analytical formulas for the eigenfrequencies are derived for limiting
cases
Non-equilibrium Green's function approach to inhomogeneous quantum many-body systems using the Generalized Kadanoff Baym Ansatz
In non-equilibrium Green's function calculations the use of the Generalized
Kadanoff-Baym Ansatz (GKBA) allows for a simple approximate reconstruction of
the two-time Green's function from its time-diagonal value. With this a drastic
reduction of the computational needs is achieved in time-dependent
calculations, making longer time propagation possible and more complex systems
accessible. This paper gives credit to the GKBA that was introduced 25 years
ago. After a detailed derivation of the GKBA, we recall its application to
homogeneous systems and show how to extend it to strongly correlated,
inhomogeneous systems. As a proof of concept, we present results for a
2-electron quantum well, where the correct treatment of the correlated electron
dynamics is crucial for the correct description of the equilibrium and dynamic
properties
On the Coulomb-dipole transition in mesoscopic classical and quantum electron-hole bilayers
We study the Coulomb-to-dipole transition which occurs when the separation
of an electron-hole bilayer system is varied with respect to the
characteristic in-layer distances. An analysis of the classical ground state
configurations for harmonically confined clusters with reveals that
the energetically most favorable state can differ from that of two-dimensional
pure dipole or Coulomb systems. Performing a normal mode analysis for the N=19
cluster it is found that the lowest mode frequencies exhibit drastic changes
when is varied. Furthermore, we present quantum-mechanical ground states
for N=6, 10 and 12 spin-polarized electrons and holes. We compute the
single-particle energies and orbitals in self-consistent Hartree-Fock
approximation over a broad range of layer separations and coupling strengths
between the limits of the ideal Fermi gas and the Wigner crystal
- …
