Publications (43)
Nucleation in dilute 3He-4He liquid mixtures at low temperatures
M. Barranco, M. Guilleumas, D. M. Jezek +3
We present a study of phase separation from supersaturated 3He-4He liquid mixtures at low temperatures addressing both the degree of critical supersaturation Dx and the thermal-to-…
A dipolar self-induced bosonic Josephson junction
M. Abad, M. Guilleumas, R. Mayol +2
We propose a new scheme for observing Josephson oscillations and macroscopic quantum self-trapping phenomena in a toroidally confined Bose-Einstein condensate: a dipolar self-induc…
Towards a density functional description of liquid pH2
J. Navarro, F. Ancilotto, M. Barranco +1
A finite-temperature density functional approach to describe the properties of parahydrogen in the liquid-vapor coexistence region is presented. The first proposed functional is ze…
Electronic structure of few-electron concentric double quantum rings
J. I. Climente, J. Planelles, M. Barranco +2
The ground state structure of few-electron concentric double quantum rings is investigated within the local spin density approximation. Signatures of inter-ring coupling in the add…
Far-infrared edge modes in quantum dots
E. Lipparini, N. Barberan, M. Barranco +2
We have investigated edge modes of different multipolarity sustained by quantum dots submitted to external magnetic fields. We present a microscopic description based on a variatio…
Critical frequency for vortex nucleation in Bose-Fermi mixtures in optical lattices
M. Guilleumas, M. Centelles, M. Barranco +2
We investigate within mean-field theory the influence of a one-dimensional optical lattice and of trapped degenerate fermions on the critical rotational frequency for vortex line c…
Towards a QMC-based density functional including finite-range effects: excitation modes of a K quantum droplet
V. CikojeviÄ, L. VranjeÅ¡ MarkiÄ, M. Pi +2
Some discrepancies between experimental results on quantum droplets made of a mixture of K atoms in different hyperfine states and their analysis within extended Gross-Pitae…
Alkali Atoms Attached to He Nanodroplets
R. Mayol, F. Ancilotto, M. Barranco +3
We have experimentally studied the electronic excitation of Na atoms attached to He droplets by means of laser-induced fluorescence as well as beam depletion spectros…
Stability of vortex lines in liquid 3He-4He mixtures at zero temperature
D. Jezek, M. Guilleumas, M. Pi +1
At low temperatures and 3He concentrations below 6.6 %, there is experimental evidence about the existence in liquid helium mixtures, of stable vortices with 3He-rich cores. When t…
Coexistence of vortex arrays and surface capillary waves in spinning prolate superfluid He-4 nanodroplets
M. Pi, J. M. Escartin, F. Ancilotto +1
Within Density Functional Theory, we have studied the interplay between vortex arrays and capillary waves in spinning prolate He-4 droplets made of several thousands of helium atom…
K-Rb Fermi-Bose mixtures: vortical states and sag
D. M. Jezek, M. Barranco, M. Guilleumas +2
We study a confined mixture of bosons and fermions in the quantal degeneracy regime with attractive boson-fermion interaction. We discuss the effect that the presence of vortical s…
Ultrafast relaxation of photoexcited superfluid He nanodroplets
M. Mudrich, A. LaForge, F. Stienkemeier +21
The relaxation of photoexcited nanosystems is a fundamental process of light-matter interaction. Depending on the couplings of the internal degrees of freedom, relaxation can be ul…
Phase-slippage and self-trapping in a self-induced bosonic Josephson junction
M. Abad, M. Guilleumas, R. Mayol +2
A dipolar condensate confined in a toroidal trap constitutes a self-induced Josepshon junction when the dipoles are oriented perpendicularly to the trap symmetry axis and the s-wav…
Merging of superfluid Helium nanodroplets with vortices
J. M. Escartin, F. Ancilotto, M. Barranco +1
Within Density Functional Theory, we have investigated the coalescence dynamics of two superfluid helium nanodroplets hosting vortex lines in different relative orientations, which…
Energy barriers for vortex nucleation in dipolar condensates
M. Abad, M. Guilleumas, R. Mayol +2
We consider singly-quantized vortex states in a condensate of 52Cr atoms in a pancake trap. We obtain the vortex solutions by numerically solving the Gross-Pitaevskii equation in t…
Magnetic field dependence of hole levels in self-assembled InAs quantum dots
J. I. Climente, J. Planelles, M. Pi +1
Recent magneto-transport experiments of holes in InGaAs quantum dots [D. Reuter, P. Kailuweit, A.D. Wieck, U. Zeitler, O. Wibbelhoff, C. Meier, A. Lorke, and J.C. Maan, Phys. Rev.…
Isospin phases of vertically coupled double quantum rings under the influence of perpendicular magnetic fields
M. Royo, F. Malet, M. Barranco +2
Vertically coupled double quantum rings submitted to a perpendicular magnetic field are addressed within the local spin-density functional theory. We describe the structure of…
Desorption Dynamics of Heavy Alkali Metal Atoms (Rb, Cs) off the Surface of Helium Nanodroplets
J. von Vangerow, A. Sieg, F. Stienkemeier +6
We present a combined ion imaging and density functional theory study of the dynamics of the desorption process of rubidium and cesium atoms off the surface of helium nanodroplets…
Quantum cavitation in liquid helium
M. Guilleumas, M. Barranco, D. M. Jezek +2
Using a functional-integral approach, we have determined the temperature below which cavitation in liquid helium is driven by thermally assisted quantum tunneling. For both helium…
Finite size effects in adsorption of helium mixtures by alkali substrates
M. Barranco, M. Guilleumas, E. S. Hernandez +3
We investigate the behavior of mixed 3He-4He droplets on alkali surfaces at zero temperature, within the frame of Finite Range Density Functional theory. The properties of one sing…
Dipolar condensates confined in a toroidal trap: ground state and vortices
M. Abad, M. Guilleumas, R. Mayol +2
We study a Bose-Einstein condensate of 52Cr atoms confined in a toroidal trap with a variable strength of s-wave contact interactions. We analyze the effects of the anisotropic nat…
Generating vortex rings in Bose-Einstein condensates in the line-source approximation
M. Guilleumas, D. M. Jezek, R. Mayol +2
We present a numerical method for generating vortex rings in Bose-Einstein condensates confined in axially symmetric traps. The vortex ring is generated using the line-source appro…
Ring vortex destabilization in supersaturated 3He-4He liquid mixtures at low temperatures
D. M. Jezek, M. Pi, M. Barranco +2
The effect of ring vortices on the destabilization of supersaturated liquid helium mixtures at very low temperatures is investigated as a function of pressure. We have found that l…
Multipole excitations in quantum dots
A. Emperador, M. Barranco, E. Lipparini +2
We have employed time-dependent local-spin density theory to analyze the multipole spin and charge density excitations recently found in GaAs-AlGaAs quatum dots [C. Schüller et al…
The structure and energetics of He and He nanodroplets doped with alkaline earth atoms
A. Hernando, R. Mayol, M. Pi +4
We present systematic results, based on density functional calculations, for the structure and energetics of He and He nanodroplets doped with alkaline earth atoms. We pred…
Vortices in dipolar condensates with dominant dipolar interactions
M. Abad, M. Guilleumas, R. Mayol +2
We present full three-dimensional numerical calculations of single vortex states in rotating dipolar condensates. We consider a Bose-Einstein condensate of 52Cr atoms with dipole-d…
Surface location of sodium atoms attached to He-3 nanodroplets
F. Stienkemeier, O. Bunermann, R. Mayol +3
We have experimentally studied the electronic excitation of Na atoms attached to He droplets by means of laser-induced fluorescence as well as beam depletion…
Bound states of 3He at the edge of a 4He drop on a cesium surface
R. Mayol, M. Barranco, E. S. Hernandez +2
We show that small amounts of 3He atoms, added to a 4He drop deposited on a flat cesium surface at zero temperature, populate bound states localized at the contact line. These edge…
Time-resolved study of resonant interatomic Coulombic decay in helium nanodroplets
A. C. LaForge, R. Michiels, Y. Ovcharenko +30
When weakly-bound complexes are multiply excited by intense electromagnetic radiation, energy can be exchanged between neighboring atoms through a type of resonant interatomic Coul…
Thermally assisted quantum cavitation in solutions of 3He in 4He
D. Jezek, M. Guilleumas, M. Pi +1
We have investigated the quantum-to-thermal crossover temperature T* for cavitation in liquid helium mixtures up to 0.05 3He concentrations. With respect to the pure 4He case, T* i…
Dissociation of vertical semiconductor diatomic artificial molecules
M. Pi, A. Emperador, M. Barranco +4
We investigate the dissociation of few-electron circular vertical semiconductor double quantum dot artificial molecules at 0 T as a function of interdot distance. Slight mismatch i…
Bose-Fermi Mixtures in Optical Lattices
M. Centelles, M. Guilleumas, M. Barranco +2
Using mean field theory, we have studied Bose-Fermi mixtures in a one-dimensional optical lattice in the case of an attractive boson-fermion interaction. We consider that the fermi…
Freezing of He-4 and its liquid-solid interface from Density Functional Theory
F. Ancilotto, M. Barranco, F. Caupin +2
We show that, at high densities, fully variational solutions of solid-like type can be obtained from a density functional formalism originally designed for liquid 4He. Motivated by…
Magnetoplasmons in quantum rings
A. Emperador, M. Barranco, E. Lipparini +2
We have studied the structure and dipole charge density response of nanorings as a function of the magnetic field using local-spin density functional theory. Two small rings consis…
Surface location of sodium atoms attached to He nanodroplets
F. Stienkemeier, O. Bünermann, R. Mayol +3
We have experimentally studied the electronic excitation of Na atoms attached to He droplets by means of laser-induced fluorescence as well as beam depletion…
A vertical diatomic artificial molecule in the intermediate coupling regime in a parallel and perpendicular magnetic field
F. Ancilotto, D. G. Austing, M. Barranco +4
We present experimental results for the ground state electrochemical potentials of a few electron semiconductor artificial molecule made by vertically coupling two quantum dots, in…
Transverse dipole spin modes in quantum dots
E. Lipparini, M. Barranco, A. Emperador +2
We have carried out a systematic analysis of the transverse dipole spin response of a large size quantum dot within time-dependent current density functional theory. Results for ma…
Cavitation of Electrons Bubbles in Liquid Helium Below saturation Pressure
M. Pi, M. Barranco, R. Mayol +1
We have used a Hartree-type electron-helium potential together with a density functional description of liquid He and He to study the explosion of electron bubbles submitte…
From nonwetting to prewetting: the asymptotic behavior of 4He drops on alkali substrates
M. Barranco, M. Guilleumas, E. S. Hernandez +3
We investigate the spreading of 4He droplets on alkali surfaces at zero temperature, within the frame of Finite Range Density Functional theory. The equilibrium configurations of s…
Far-infrared excitations in a quantum antidot at finite magnetic fields
A. Emperador, M. Pi, M. Barranco +2
We have investigated the far-infrared dipole modes of a quantum antidot submitted to a perpendicularly applied magnetic field B. The ground state of the antidot is described within…
Propagation of collective modes in non-overlapping dipolar Bose-Einstein condensates
A. GallemÃ, M. Guilleumas, R. Mayol +1
We investigate long-range effects of the dipolar interaction in Bose-Einstein condensates by solving the time-dependent 3D Gross-Pitaevskii equation. We study the propagation of ex…
Spin and density longitudinal response of quantum dots in time-dependent local-spin-density approximation
Ll. Serra, M. Barranco, A. Emperador +2
The longitudinal dipole response of a quantum dot has been calculated in the far-infrared regime using local spin density functional theory. We have studied the coupling between th…
Multipole modes and spin features in the Raman spectrum of nanoscopic quantum rings
A. Emperador, M. Pi, M. Barranco +1
We present a systematic study of ground state and spectroscopic properties of many-electron nanoscopic quantum rings. Addition energies at zero magnetic field (B) and electro-chemi…