| 1. |
- Castellini, Alessia, et al.
(författare)
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Quantum plasmonics with multi-emitters: application to stimulated Raman adiabatic passage
- 2018
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Ingår i: European Physical Journal D. - : Springer Science and Business Media LLC. - 1434-6079 .- 1434-6060. ; 72:12
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: We construct a mode-selective effective model describing the interaction of the localised surface plasmon polaritons (LSPs) supported by a spherical metal nanoparticle (MNP) with N quantum emitters (QEs) in an arbitrary geometric arrangement. Simplifying previously presented procedures, we develop a formulation in which the field response in the presence of the MNP can be decomposed into orthogonal modes, expanding the Green tensor of the system in the spherical vector harmonics basis and using the generalized global Löwdin orthogonalization algorithm. We investigate the possibility of using the LSPs as mediators of an efficient control of population transfer between two QEs. We show that a Stimulated Raman Adiabatic Passage (STIRAP) configuration allows such a transfer via a decoherence-free dark state for a specific range of angular distances between the QEs, when they are located very close to the MNP. The transfer is otherwise blocked. We explain this blockade by the destructive superposition of all the plasmonic modes. Graphical abstract: [Figure not available: see fulltext.].
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| 2. |
- Emile, Olivier, et al.
(författare)
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Mechanism of angular momentum transfer from microwaves to a copper ring
- 2016
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Ingår i: European Physical Journal D. - : Springer Science and Business Media LLC. - 1434-6060 .- 1434-6079. ; 70:8
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Tidskriftsartikel (refereegranskat)abstract
- In the exchange of orbital angular momentum between an electromagnetic wave and a copper ring we examine the origin of the Angular Momentum. We then investigate the transfer mechanism between the microwave and the object, and compare it with other mechanisms. We evidence a transfer mechanism based on the reflection of the electromagnetic field on the copper ring. In particular, at a microscopic scale, we show that the electromagnetic field induces alternative electric currents in the ring, with a small drift. Although little, the resistivity of copper leads to a force that rotates the ring. The estimation of the torque, which is of the order of 10(-8) Nm, is in good agreement with the experimental measurements. We also show that the transfer of electromagnetic orbital angular momentum to objects could be a way to measure the orbital angular momentum carried by electromagnetic fields, and we discuss possible applications.
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| 3. |
- Essén, Hanno, et al.
(författare)
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Drift velocity of charged particles in magnetic fields and its relation to the direction of the source current
- 2016
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Ingår i: European Physical Journal D. - : Springer. - 1434-6060 .- 1434-6079. ; 70:10
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: Integrable motion of charged particles in magnetic fields produced by stationary currentdistributions is investigated. We treat motion in the magnetic field from an infinite flatcurrent sheet, a Harris current sheath, an infinite rectilinear current, and a dipole inits equatorial plane. We find that positively charged particles as a rule will drift inthe same direction as the current that is the source of the magnetic field in question.The conclusion is that charged particles moving under the influence of currentdistributions tend to enhance the current and that this indicates currentself-amplification. Graphical abstract: [Figure not available: see fulltext.]
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| 4. |
- Fülöp, Tünde, 1970, et al.
(författare)
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Relativistic laser plasma interactions
- 2017
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Ingår i: European Physical Journal D. - : Springer Science and Business Media LLC. - 1434-6079 .- 1434-6060. ; 71:11
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 5. |
- Greiner, Franko, et al.
(författare)
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Diagnostics and characterization of nanodust and nanodusty plasmas
- 2018
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Ingår i: European Physical Journal D. - : SPRINGER. - 1434-6060 .- 1434-6079. ; 72:5
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Tidskriftsartikel (refereegranskat)abstract
- Plasmas growing or containing nanometric dust particles are widely used and proposed in plasma technological applications for production of nano-crystals and surface deposition. Here, we give a compact review of in situ methods for the diagnostics of nanodust and nanodusty plasmas, which have been developed in the framework of the SFB-TR24 to fully characterize these systems. The methods include kinetic Mie ellipsometry, angular-resolved Mie scattering, and 2D imaging Mie ellipsometry to get information about particle growth processes, particle sizes and particle size distributions. There, also the role of multiple scattering events is analyzed using radiative transfer simulations. Computed tomography and Abel inversion techniques to get the 3D dust density profiles of the particle cloud will be presented. Diagnostics of the dust dynamics yields fundamental dust and plasma properties like particle charges and electron and ion densities. Since nanodusty plasmas usually form dense dust clouds electron depletion (Haynes effect) is found to be significant.
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| 6. |
- Ibrakovic, Neven, et al.
(författare)
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Achromatic dual-waveplate for inline two color high-order harmonic generation
- 2018
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Ingår i: European Physical Journal D. Atomic, Molecular, Optical and Plasma Physics. - : Springer Science and Business Media LLC. - 1434-6060. ; 72:9
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: We propose a design of an achromatic dual-waveplate intended to align the polarization of orthogonal two-color pulses in an inline configuration. The waveplate acts as a half-waveplate for pulses with a carrier wavelength of 1300 nm over a bandwidth of 300 nm. For the second harmonic of the pulses the waveplate acts as a full-waveplate, centered at 650 nm with a bandwidth of 100 nm. By experimentally measuring the transmission of this optic when placed between two parallel linear polarizers we show that the polarization directions are aligned as expected. This experiment is then verified by calculating the transmission through the optic using Jones calculus. This waveplate could be useful in two-color experiments with few-cycle pulses, or pulses with a tunable wavelength, that need to be aligned with their second harmonics. Graphical abstract: [Figure not available: see fulltext.].
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| 7. |
- Mackenroth, Felix, 1984, et al.
(författare)
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Reaching high flux in laser-driven ion acceleration
- 2017
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Ingår i: European Physical Journal D. - : Springer Science and Business Media LLC. - 1434-6079 .- 1434-6060. ; 71:8
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Tidskriftsartikel (refereegranskat)abstract
- Since the first experimental observation of laser-driven ion acceleration, optimizing the ion beams’ characteristics aiming at levels enabling various key applications has been the primary challenge driving technological and theoretical studies. However, most of the proposed acceleration mechanisms and strategies identified as promising, are focused on providing ever higher ion energies. On the other hand, the ions’ energy is only one of several parameters characterizing the beams’ aptness for any desired application. For example, the usefulness of laser-based ion sources for medical applications such as the renowned hadron therapy, and potentially many more, can also crucially depend on the number of accelerated ions or their flux at a required level of ion energies. In this work, as an example of an up to now widely disregarded beam characteristic, we use theoretical models and numerical simulations to systematically examine and compare the existing proposals for laser-based ion acceleration in their ability to provide high ion fluxes at varying ion energy levels.
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| 8. |
- Magnusson, Joel, 1991, et al.
(författare)
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Energy partitioning and electron momentum distributions in intense laser-solid interactions
- 2017
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Ingår i: European Physical Journal D. - : Springer Science and Business Media LLC. - 1434-6079 .- 1434-6060. ; 71:9
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Tidskriftsartikel (refereegranskat)abstract
- Producing inward orientated streams of energetic electrons by intense laser pulses acting on solid targets is the most robust and accessible way of transferring the laser energy to particles, which underlies numerous applications, ranging from TNSA to laboratory astrophysics. Structures with the scale of the laser wavelength can significantly enhance energy absorption, which has been in the center of attention in recent studies. In this article, we demonstrate and assess the effect of the structures for widening the angular distribution of generated energetic electrons. We analyse the results of PIC simulations and reveal several aspects that can be important for the related applications.
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| 9. |
- Mahabal, Manasi S., et al.
(författare)
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Rare earth functionalization effect in optical response of ZnO nano clusters
- 2016
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Ingår i: European Physical Journal D. - : Springer Science and Business Media LLC. - 1434-6060 .- 1434-6079. ; 70:3
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Tidskriftsartikel (refereegranskat)abstract
- The electronic structure of rare earth (RE) doped Zn12O12 clusters - namely, REZn11O12 and RE2Zn10O12 with RE = Nd, Eu and Gd have been investigated within the framework of density functional theory formalism. Doping of a RE atom is found to be energetically favorable in this zinc oxide cluster. We have found that the cage structure of the host cluster Zn12O12 does not change significantly by the substitutional doping of a RE atom on Zn sites. The magnetic coupling between RE ions in the host cluster is found to be ferromagnetic. The static polarizabilities and optical properties of the RE doped Zn12O12 clusters have been studied based on the time dependent density functional theory. With RE doping, the polarizability increases as compared to that of the host cluster. The analysis of the optical absorption spectra indicate that the f electrons in RE doped clusters are significantly more involved in low-energy transitions. For Eu doped clusters give rise to more quenched oscillator strengths as compared to that of Nd and Gd doped zinc oxide clusters. With the increase in number of RE atoms, the red shift is observed in the optical spectrum of the zinc oxide cluster.
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| 10. |
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