A. V. Filinov

• PD. Dr.
• Research Assistant at Kiel University

Accurate knowledge of the properties of hydrogen at high compression is crucial for astrophysics (e.g., planetary and stellar interiors, brown dwarfs, atmosphere of compact stars) and laboratory experiments, including inertial confinement fusion. There exists experimental data for the equation of state, conductivity, and Thomson scattering spectra....

Accurate knowledge of the properties of hydrogen at high compression is crucial for astrophysics (e.g. planetary and stellar interiors, brown dwarfs, atmosphere of compact stars) and laboratory experiments, including inertial confinement fusion. There exists experimental data for the equation of state, conductivity, and Thomson scattering spectra....

We present improved first-principle fermionic path integral Monte Carlo (PIMC) simulation results for a dense partially ionized hydrogen (deuterium) plasma, for temperatures in the range 15000K≤T≤400000K and densities 7×10−7g/cm3≤ρH≤0.085g/cm3 (1.4×10−6g/cm3≤ρD≤0.17g/cm3), corresponding to 100≥rs≥2, where rs=r¯/aB is the ratio of the mean interpart...

We present novel first-principle fermionic path integral Monte Carlo (PIMC) simulation results for a dense partially ionized hydrogen (deuterium) plasma, for temperatures in the range $15,000$K $\leq T \leq 400,000$K and densities $7 \cdot 10^{-7}$g/cm$^{3}\leq \rho_H \leq 0.085$ g/cm$^{3}$ ($1.4 \cdot 10^{-6}$g/cm$^{3}\leq \rho_D \leq 0.17$ g/cm$^...

In a recent Letter [T. Dornheim et al., Phys. Rev. Lett. 121, 255001 (2018)], it was predicted on the basis of ab initio quantum Monte Carlo simulations that, in a uniform electron gas, the peak ω0 of the dynamic structure factor S(q,ω) exhibits an unusual nonmonotonic wave number dependence, where dω0/dq<0, at intermediate q, under strong coupling...

The dynamic structure factor and the eigenmodes of density fluctuations in liquid ³He are studied using a novel non-perturbative approach. This new version of the self-consistent method of moments invokes up to nine sum rules and other exact relations, the two-parameter Shannon information entropy maximization procedure, and the ab initio path inte...

Dynamical properties of uniform electron fluids are studied within a nonperturbative approach consisting in the combination of the self-consistent version of the method of moments (SCMM) involving up to nine sum rules and other exact relations, the two-parameter Shannon information entropy maximization procedure, and the ab initio path integral Mon...

Dynamical properties of uniform electron fluids are studied within a nonperturbative approach consisting in the combination of the self-consistent version of the method of moments (SCMM) involving up to nine sum rules and other exact relations, the two-parameter Shannon information entropy maximization procedure, and the abinitio path integral Mont...

In a recent Letter [T. Dornheim \textit{et al.}, Phys. Rev. Lett. \textbf{121}, 255001 (2018)], it was predicted on the basis of \textit{ab initio} quantum Monte Carlo simulations that, in a uniform electron gas, the peak $\omega_0$ of the dynamic structure factor $S(q,\omega)$ exhibits an unusual non-monotonic wave number dependence, where $d\omeg...

Günter Kelbg did remarkable early work in the field of quantum statistical physics, in particular for dense quantum plasmas. In 2022 we celebrated his 100th birthday. On this occasion, we give a brief overview of his main scientific achievements in the field of quantum plasmas, complemented by some biographical background of his research and teachi...

Dynamical properties of uniform electron fluids (jellium model) are studied within a novel non-perturbative approach consisting in the combination of the self-consistent version of the method of moments (SCMM) involving up to nine sum rules and other exact relations, the two-parameter Shannon information entropy maximization procedure, and the ab i...

The density-density dynamic structure factor and the eigenmodes of density fluctuations in the uniform liquid $^3$He are studied using a novel non-perturbative approach. The introduced self-consistent method of moments invokes up to nine sum rules and other exact relations involving the spectral density, the two-parameter Shannon information entrop...

The uniform electron gas (UEG) is one of the key models for the understanding of warm dense matter—an exotic, highly compressed state of matter between solid and plasma phases. The difficulty in modelling the UEG arises from the need to simultaneously account for Coulomb correlations, quantum effects, and exchange effects, as well as finite tempera...

In a classical plasma the momentum distribution, n(k), decays exponentially, for large k, and the same is observed for an ideal Fermi gas. However, when quantum and correlation effects are relevant simultaneously, an algebraic decay, n∞(k)∼k−8 has been predicted. This is of relevance for cross sections and threshold processes in dense plasmas that...

In a classical plasma the momentum distribution, $n(k)$, decays exponentially, for large $k$, and the same is observed for an ideal Fermi gas. However, when quantum and correlation effects are relevant simultaneously, an algebraic decay, $n_\infty(k)\sim k^{-8}$ has been predicted. This is of relevance for cross sections and threshold processes in...

Warm dense matter (WDM)—an exotic state of highly compressed matter—has attracted increased interest in recent years in astrophysics and for dense laboratory systems. At the same time, this state is extremely difficult to treat theoretically. This is due to the simultaneous appearance of quantum degeneracy, Coulomb correlations, and thermal effects...

Warm dense matter (WDM) -- an exotic state of highly compressed matter -- has attracted high interest in recent years in astrophysics and for dense laboratory systems. At the same time, this state is extremely difficult to treat theoretically. This is due to the simultaneous appearance of quantum degeneracy, Coulomb correlations and thermal effects...

Being motivated by the surge of fermionic quantum Monte Carlo simulations at finite temperature, we present a detailed analysis of the permutation-cycle properties of path integral Monte Carlo (PIMC) simulations of degenerate electrons. Particular emphasis is put onto the uniform electron gas in the warm dense matter regime. We carry out PIMC simul...

Solids facing a plasma are a common situation in many astrophysical systems and laboratory setups. Moreover, many plasma technology applications rely on the control of the plasma-surface interaction, i.e., of the particle, momentum and energy fluxes across the plasma-solid interface. However, presently often a fundamental understanding of them is m...

Being motivated by the surge of fermionic quantum Monte Carlo simulations at finite temperature, we present a detailed analysis of the permutation-cycle properties of path integral Monte Carlo (PIMC) simulations of degenerate electrons. Particular emphasis is put onto the uniform electron gas in the warm dense matter regime. We carry out PIMC simul...

Solids facing a plasma are a common situation in many astrophysical systems and laboratory setups. Moreover, many plasma technology applications rely on the control of the plasma-surface interaction. However, presently often a fundamental understanding of them is missing, so most technological applications are being developed via trial and error. I...

The physical processes at the interface of a lowerature plasma and a solid are extremely complex. They involve a huge number of elementary processes in the plasma, in the solid as well as charge, momentum and energy transfer across the interface. In the majority of plasma simulations these surface processes are either neglected or treated via pheno...

A new combination of first principle molecular dynamics (MD) simulations with a rate equation model presented in the preceding paper (paper I) is applied to analyze in detail the scattering of argon atoms from a platinum (111) surface. The combined model is based on a classification of all atom trajectories according to their energies into trapped,...

A combination of first principle molecular dynamics (MD) simulations with a rate equation model (MD-RE approach) is presented to study the trapping and the scattering of rare gas atoms from metal surfaces. The temporal evolution of the atom fractions that are either adsorbed or scattered into the continuum is investigated in detail. We demonstrate...

The physical processes at the plasma-solid interface are extremely complex. They involve a huge number of elementary processes in the plasma, in the solid as well as charge, momentum and energy transfer across the interface. Even though the equations of motion for the participating charged and neutral particles are known, in principle, first princi...

A new combination of first principle molecular dynamics (MD) simulations with a rate equation model presented in the preceding paper (paper I) is applied to analyze in detail the scattering of argon atoms from a platinum (111) surface. The combined model is based on a classification of all atom trajectories according to their energies into trapped,...

A combination of first principle molecular dynamics (MD) simulations with a rate equation model (MD-RE approach) is presented to study the trapping and the scattering of rare gas atoms from metal surfaces. The temporal evolution of the atom fractions that are either adsorbed or scattered into the continuum is investigated in detail. We demonstrate...

The understanding of correlations in degenerate nonideal many-particle systems is complex and theoretically challenging. Using the recently proposed permutation blocking path integral Monte Carlo (PB-PIMC) scheme, which allows for an exact treatment of many-body correlations, we study the influence of quantum statistics in a confined few-particle C...

A two-component two-dimensional (2D) dipolar bosonic system in the bilayer geometry is considered. By performing quantum Monte Carlo simulations in a wide range of layer spacings we analyze in detail the pair correlation functions, the static response function, the kinetic and interaction energies. By reducing the layer spacing we observe a transit...

A two-component two-dimensional (2D) dipolar bosonic system in the bilayer geometry is considered. By performing quantum Monte Carlo simulations in a wide range of layer spacings we analyze in detail the pair correlation functions, the static response function, the kinetic and interaction energies. By reducing the layer spacing we observe a transit...

We explore the stability of a Wigner molecule (WM) formed in confinements with different geometries emulating the role of disorder and analyze the melting (or crossover) of such a system. Building on a recent calculation [D. Bhattacharya, A. Ghosal, Eur. Phys. J. B 86, 499 (2013)] that discussed the effects of irregularities on the thermal crossove...

The uniform electron gas (UEG) at finite temperature is of high current interest due to its key relevance for many applications including dense plasmas and laser excited solids. In particular, density functional theory heavily relies on accurate thermodynamic data for the UEG. Until recently, the only existing first-principle results had been obtai...

Correlated fermions are of high interest in condensed matter (Fermi liquids, Wigner molecules), cold atomic gases and dense plasmas. Here we propose a novel approach to path integral Monte Carlo (PIMC) simulations of strongly degenerate non-ideal fermions at finite temperature by combining a fourth-order factorization of the density matrix with ant...

We analyze the quantum melting of two-dimensional Wigner molecules (WM) in confined geometries with distinct symmetries and compare it with corresponding thermal melting. Our findings unfold complementary mechanisms that drive the quantum and thermal crossovers in a WM and show that the symmetry of the confinement plays no significant role in deter...

We analyze the superfluid phase transition of harmonically confined bosons with long-range interaction in both two and three dimensions in a broad parameter range from weak to strong coupling. We observe that the onset of superfluidity occurs in $3D$ at significantly lower temperatures compared to $2D$. This is demonstrated to be a quantum degenera...

We investigate exciton bound-state formation and crystallization effects in two-dimensional electron-hole bilayers. Performing unbiased path integral Monte Carlo simulations all quantum and Coulomb correlation effects are treated on first principles. We analyze diverse pair distribution functions in dependence on the layer separation, particle dens...

The Berezinskii-Kosterlitz-Thouless transition in two-dimensional dipolar systems has been studied recently by path integral Monte Carlo simulations [A. Filinov et al.,Phys. Rev. Lett. 105, 070401 (2010)]. Here, we complement this analysis and study temperature-coupling strength dependence of the density (particle-hole) and single-particle (SP) exc...

Nobel metals that are deposited on a polymer surface exhibit surface diffusion and diffusion into the bulk. At the same time the metal atoms tend to form clusters because their cohesive energy is about two orders of magnitude higher than the cohesive energy of polymers. To selfconsistently simulate these coupled processes, we present in this paper...

A novel path integral Monte Carlo (PIMC) approach for correlated many-particle systems with arbitrary pair interaction in continuous space at low temperatures is presented. It is based on a representation of the N -particle density operator in a basis of (anti-)symmetrized N -particle states (configurations of occupation numbers). The path integral...

Indirect excitons -- pairs of electrons and holes spatially separated in semiconductor bilayers or quantum wells -- are known to undergo Bose-Einstein condensation and to form a quantum fluid. Here we show that this superfluid may crystallize upon compression. However, further compression results in quantum melting back to a superfluid. This unusua...

Plasmas are generally associated with a hot gas of charged particles which behave classically. However, when the temperature is lowered and/or the density is increased sufficiently, the plasma particles (most importantly, electrons) become quantum degenerate, that is, the extension of their wave functions becomes comparable to the distance between...

Spontaneous, correlation-driven structure formation is one of the most fundamental collective processes in nature. In particular, particle ensembles in externally controlled confinement geometries allow for a systematic investigation of strong correlation and quantum effects over broad ranges of the relevant trap and plasma parameters. An exception...

The superfluid to normal fluid transition of dipolar bosons in two dimensions is studied throughout the whole density range using path integral Monte Carlo simulations and summarized in the phase diagram. While at low densities, we find good agreement with the universal results depending only on the scattering length $a_s$, at moderate and high den...

We present compelling evidence supporting the conjecture that the origin of the roton in Bose-condensed systems arises from strong correlations between the constituent particles. By studying the two dimensional bosonic dipole systems a paradigm, we find that classical molecular dynamics (MD) simulations provide a faithful representation of the disp...

Semi-classical methods of statistical mechanics can incorporate essential quantum effects by using effective quantum potentials. An ideal Fermi gas interacting with an impurity is represented by a classical fluid with effective electron-electron and electron-impurity quantum potentials. The electron-impurity quantum potential is evaluated at weak c...

Using an adiabatic approximation we derive an effective interaction potentially for spatially indirect excitons. Using this potential and path integral Monte Carlo simulations we study exciton crystllization and the quantum melting phase transition in a macroscopic system of 2D excitons. Furthermore, the superfluid fraction is calculated as a funct...

We report on first spectrally and spatially high resolved measurements of a recently suggested electrostatic confinement [Ludwig et al., Phys. Status Solidi B 243(10), 2363 (2006)] for excitons in a single quantum well. For this strongly correlated many-particle system we present finite-temperature quantum Monte-Carlo results and discuss the specif...

Cesium adsorption structures on Ag(111) were characterized in a low-temperature scanning tunneling microscopy experiment. At low coverages, atomic resolution of individual Cs atoms is occasionally suppressed in regions of an otherwise hexagonally ordered adsorbate film on terraces. Close to step edges Cs atoms appear as elongated protrusions along...

We study the Coulomb-to-dipole transition which occurs when the separation $d$ 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 $N\leq30$ reveals that the energetically most favorable state can differ f...

In the tomography representation we propose a new approach, which describes the dynamics of quantum particles by the Kolmogorov equations for non-negative propagators. To solve the Kolmogorov equations we use a diffusive Markovian random processes described by the related nonlinear stochastic Langevin equations. As a result the dynamics of quantum...

When a few identical charged particles are trapped in a spherical electric field at low temperature, they form concentric shells resembling atoms. The behavior of these "artificial atoms" is easily controlled by varying the field strength. In particular, it is possible to transfer the system from a liquidlike to a crystal-like state. We analyze art...

Strong correlation effects in classical and quantum plasmas are discussed. In particular, Coulomb (Wigner) crystallization phenomena are reviewed focusing on one-component non-neutral plasmas in traps and on macroscopic two-component neutral plasmas. The conditions for crystal formation in terms of critical values of the coupling parameters and the...

In small confined systems predictions for the melting point strongly depend on the choice of quantity and on the way it is computed, even yielding divergent and ambiguous results. We present a very simple quantity that allows us to control these problems-the variance of the block averaged interparticle distance fluctuations.

In small confined systems predictions for the melting point strongly depend on the choice of quantity and on the way it is computed, even yielding divergent and ambiguous results. We present a very simple quantity which allows to control these problems -- the variance of the block averaged interparticle distance fluctuations.

We consider Coulomb crystal formation in quantum electron-ion (hole) bilayers. Varying the mass ratio M of ions and electrons between 1 and 100 for a fixed layer separation d at low temperature and high density, one can tune the hole behavior from delocalized (quantum) to localized (quasi-classical) while the electrons remain delocalized all the ti...

Classical molecular dynamics (MD) is a well established and powerful tool in various fields of science, e.g. chemistry, plasma physics, cluster physics and condensed matter physics. Objects of investigation are few-body systems and many-body systems as well. The broadness and level of sophistication of this technique is documented in many monograph...

The ground state of an externally confined one-component Yukawa plasma is derived analytically using the local density approximation (LDA). In particular, the radial density profile is computed. The results are compared with the recently obtained mean-field (MF) density profile [Henning et al., Phys. Rev. E 74, 056403 (2006)]. While the MF results...

A hierarchy of models is presented to study the basic physics of dust in RF laboratory plasmas in close connection to experiments. Here, the full spatial and temporal kinetics of all species is followed with different complexity in the inclusion of dust particles. The model results are compared to experimental findings.

We consider a \textit{mass-asymmetric} electron and hole bilayer. Electron and hole Coulomb correlations and electron and hole quantum effects are treated on first princles by path integral Monte Carlo methods. For a fixed layer separation we vary the mass ratio $M$ of holes and electrons between 1 and 100 and analyze the structural changes in the...

A hierarchy of models is presented to study the basic physics of dust in RF laboratory plasmas in close connection to experiments. Here, the full spatial and temporal kinetics of all species is followed with different complexity in the inclusion of dust particles. The model results are compared to experimental findings.

The ground state of an externally confined one-component Yukawa plasma is derived analytically using the local density approximation (LDA). In particular, the radial density profile is computed. The results are compared with the recently obtained mean-field (MF) density profile \cite{henning.pre06}. While the MF results are more accurate for weak s...

Superfluidity in a trapped cloud of quantum particles is defined using the cloud's response to a rotation of the external potential (non classical moment of inertia, NCRI). While NCRI originates from inter-particle interactions. in finite trapped quantum systems, due to the discrete nature of the spectrum, the NCRI effect occurs in any case regardl...

This chapter is devoted to the computation of equilibrium (thermodynamic) properties of quantum systems. In particular, we will be interested in the situation where the interaction between particles is so strong that it cannot be treated as a small perturbation. For weakly coupled systems many efficient theoretical and computational techniques do e...

Classical molecular dynamics (MD) is a well established and powerful tool in various fields of science, e.g. chemistry, plasma physics, cluster physics and condensed matter physics. Objects of investigation are few-body systems and many-body systems as well. The broadness and level of sophistication of this technique is documented in many monograph...

Spherical Coulomb crystals in dusty plasmas [1] are well described by an isotropic Yukawa-type pair interaction and an external parabolic confinement as was shown by extensive molecular dynamics simulations [2]. A much simpler description is possible with analytical shell models which have been derived for Yukawas plasmas in [3,4]. Here we analyze...

First principle results for small clusters of strongly correlated indirect excitons in a harmonic confinement potential are presented. At low temperature Bose condensation is verified. The condensate fraction and the superfluid density are computed. The importance of a correct treatment of the Fermi statistics of electrons and holes is demonstrated...

In this contribution we consider small ensembles of optically excited indirect excitons in a single quantum well. Using Path Integral Monte Carlo we compute from first principles the spatial separation of electrons and holes and the lateral quantum Stark confinement of the excitons in the quantum well which is produced by an external electric field...

In the limit of strong correlations, we present a general description of finite electron and exciton systems in semiconductor quantum dots or quantum wells with external electrostatic confinement. We are able to analytically obtain the energy spectrum and wave functions which are constructed by exact diagonalization of the Hamiltonian in terms of t...

This is the third volume (the first two volumes are Progress in Nonequilibrium Green's Functions, M. Bonitz (ed.) and Progress in Nonequilibrium Green's Functions II, M. Bonitz and D. Semkat (eds.), which were published by World Scientific (Singapore), in 2000 and 2003, respectively, (ISBN 981-02-4218-2 and ISBN 981-238-271-2).) of articles on the...

Classical molecular dynamics and Monte Carlo simulations are used to investigate three-dimensional spherical charged particle clusters which were experimentally observed in dusty plasmas (Arp et al 2004 Phys. Rev. Lett. 93 165005). The shell configuration and geometry of the ground state is found to change with the screening parameter. The melting...

We provide a survey of the concept and several successful applications of effective potentials. After introducing Kelbg's expression we discuss several useful approximations and additional generalizations including non-diagonal expressions. Finally, we present the recent results concerning non-diagonal contributions and the relation to effective in...

We study the Stark effect on excitonic complexes confined in a GaAs-based single quantum well. We approach this problem using Path Integral Monte Carlo methods to compute the many-body density matrix. The developed method is applied for investigation of the electric field-dependence of energies, particle distribution and effective exciton dipole mo...

This is the third volume (the first two volumes are Progress in Nonequilibrium Green's Functions, M. Bonitz (ed.) and Progress in Nonequilibrium Green's Functions II, M. Bonitz and D. Semkat (eds.), which were published by World Scientific (Singapore), in 2000 and 2003, respectively, (ISBN 981-02-4218-2 and ISBN 981-238-271-2).) of articles on the...

Small three-dimensional strongly coupled charged particles in a spherical confinement potential arrange themselves in a nested shell structure. By means of experiments, computer simulations, and theoretical analysis, the sensitivity of their structural properties to the type of interparticle forces is explored. While the normalized shell radii are...

Complex plasmas in parabolic traps [1,2], especially Coulomb balls, can easily reach a strongly coupled state which is of great current interest in many fields, including trapped ions, ultracold plasmas and condensed matter. The advantage of the dust crystals is the direct experimental access to the individual particle positions, allowing for preci...

We present an overview on classical and quantum Coulomb (Wigner) crys-tallization phenomena caused by strong correlation effects in one-component and two-component plasmas.

The ground state and the excitation spectrum of strongly correlated electrons in quantum dots are investigated. An analytical solution is constructed by exact diagonalization of the Hamiltonian in terms of the $N$-particle eigenmodes. Comment: 10 pages, 10 figures, to appear in Journal of Physics: Conf. Series

Small three-dimensional strongly coupled charged particles in a spherical confinement potential arrange themselves in a nested shell structure. By means of experiments, computer simulations and theoretical analysis, it is shown that their structural properties depend on the type of interparticle forces. Using an isotropic Yukawa interaction, quanti...

We present a detailed analysis of temperature-dependent effective quantum pair potentials. These potentials are derived from first-principle path integral Monte Carlo simulations and are accurate even at strong coupling and partial ionization. They can be efficiently used in molecular-dynamics (MD) simulations to obtain accurate thermodynamic and d...

We compare binding energies for positive and negative trions in a series of narrow GaAs quantum wells and in ``natural'' quantum dots defined by quantum well thickness fluctuations. We assign photoluminescence features to oppositely charged trions through a combination of charging behavior, luminescence polarization, and spin fine structure. Negati...

PACS 71.35.Lk, 73.20.Mf First principle results for small clusters of strongly correlated indirect excitons in a harmonic confinement potential are presented. At low temperature Bose condensation is verified. The condensate fraction and the superfluid density are computed. The importance of a correct treatment of the Fermi statistics of electrons a...

Extending our previous work [J. Phys. A 36, 5957 (2003)]], we present a detailed discussion of accuracy and practical applications of finite-temperature pseudopotentials for two-component Coulomb systems. Different pseudopotentials are discussed: (i) the diagonal Kelbg potential, (ii) the off-diagonal Kelbg potential, (iii) the improved diagonal Ke...

We present a first-principle path integral Monte-Carlo (PIMC) study of the binding energy of excitons, trions (positively and negatively charged excitons) and biexcitons bound to single-island interface defects in quasi-two-dimensional GaAs/Al$_{x}$Ga$_{1-x}$As quantum wells. We discuss in detail the dependence of the binding energy on the size of...

The influence of the well width fluctuations on the dependence of the binding energy of excitonic complexes in quantum wells is studied by using the path-integral Monte-Carlo technique. The results are compared with available experimental data and a good agreement is found.

Extending our previous work \cite{filinov-etal.jpa03ik} we present a detailed discussion of accuracy and practical applications of finite-temperature pseudopotentials for two-component Coulomb systems. Different pseudopotentials are discussed: i) the diagonal Kelbg potential, ii) the off-diagonal Kelbg potential iii) the {\em improved} diagonal Kel...

Few-particle clusters of spatially separated electrons and holes in vertically coupled two-dimensional quantum dots are analyzed. As a function of interdot distance d, the inlayer interaction between electrons (and holes) changes from Coulomb repulsion at large d to dipole repulsion of e-h pairs at small d. The change of the structural properties (...

We present first-principle path integral Monte-Carlo (PIMC) studies of strongly correlated electron–hole complexes such as excitons, trions (charged excitons) and biexcitons in AlxGa1−xAs quantum-well structures. The correlation and binding energies are calculated as function of quantum well width L, for 10 Å ≤ L ≤ 250 Å and compared with available...

The equilibrium and dynamical properties of classical and quantum bilayers with spatially separated electrons and holes are investigated by a normal mode analysis and path integral Monte-Carlo (PIMC). For the low-density limit, where the particles are classical, we present results for the eigenfrequencies and eigenmodes and analyze the dependence o...

Strong correlations in quantum Coulomb systems (QCS) are attracting increasing interest in many fields ranging from dense plasmas and semiconductors to metal clusters and ultracold trapped ions. Examples are bound states in dense plasmas (atoms, molecules, clusters) and semiconductors (excitons, trions, biexcitons) or Coulomb crystals. We present f...

Effective two-body potentials for electron–ion plasmas are analysed. Such potentials which have been previously derived by Kelbg and others capture the basic quantum diffraction effects and are exact in the weak coupling limit. Moreover, using path integral Monte Carlo (PIMC) methods, they can be applied to strongly coupled plasmas which include bo...

We present a first-principles path integral Monte Carlo study of a finite number of strongly correlated electron–hole pairs in two symmetric vertically coupled quantum dots. In this system, the intra- and interdot correlations depend on the distance d between the dots, the density n (strength of confinement potential) and temperature T. For fixed d...

A previously proposed idea (Microelectron. Eng. 63 (2002) 141) of controlling the angular mobility of electrons in a quantum dot by addition/removal of a single electron is verified and confirmed by computer simulation. Conditions for realization of the scheme in semiconductors are discussed.

We present first-principle path integral Monte-Carlo (PIMC) studies of strongly correlated electron-hole complexes such as excitons, trions (charged excitons) and biexcitons in AlxGa1-xAs quantum-well structures. The correlation and binding energies are calculated as function of quantum well width and compared with available experimental1,2,3,4 and...

Intershell rotation in small 2D Coulomb clusters in a harmonic confinement potential has been investigated with classical Molecular Dynamics simulations. Exciting rotation of the outer shell by application of a short external force, three different methods were used to determine the intershell barrier: a) from the work of the external force; b) fro...