| 1. |
- Adriani, O., et al.
(författare)
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Measurement of the flux of primary cosmic ray antiprotons with energies of 60 MeV to 350 GeV in the PAMELA experiment
- 2013
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Ingår i: JETP Letters. - 0021-3640 .- 1090-6487. ; 96:10, s. 621-627
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Tidskriftsartikel (refereegranskat)abstract
- It is interesting to measure the antiproton galactic component in cosmic rays in order to study the mechanisms by which particles and antiparticles are generated and propagate in the Galaxy and to search for new sources of, e.g., annihilation or decay of dark matter hypothetical particles. The antiproton spectrum and the ratio of the fluxes of primary cosmic ray antiprotons to protons with energies of 60 MeV to 350 GeV found from the data obtained from June 2006 to January 2010 in the PAMELA experiment are presented. The usage of the advanced data processing method based on the data classification mathematical model made it possible to increase statistics and analyze the region of higher energies than in the earlier works.
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| 2. |
- Aleksandrov, I.A., et al.
(författare)
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Linearly polarized photoluminescence from an ensemble of wurtzite GaN/AlN quantum dots
- 2010
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Ingår i: JETP Letters. - : Springer Science Business Media. - 0021-3640 .- 1090-6487. ; 91:9, s. 452-454
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Tidskriftsartikel (refereegranskat)abstract
- Microphotoluminescence from GaN/AlN quantum dots grown by molecular beam epitaxy on sapphire substrates along the (0001) axis has been studied. To produce quantum dots of different average sizes and densities, the nominal amount of deposited GaN has been varied from 1 to 4 ML. The density of the quantum dots was about 10(11) cm(-2), which corresponded to about 10(3) quantum dots excited in the experiments. The photo-luminescence from the quantum dots was linearly polarized and the maximum polarization degree (15%) has been observed for the sample with the lowest amount of deposited GaN. The photoluminescence intensity from this sample under continuous laser excitation decreased by more than two orders of magnitude for about 30 min and then stabilized. The photoluminescence intensity from other samples under continuous excitation remained constant. We suggest that a rather high polarization degree is caused by anisotropy in the strain and shape of the quantum dots formed near the dislocations, which also act as the centers of nonradiative recombination.
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| 3. |
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| 4. |
- Borman, V. D., et al.
(författare)
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Observation of electron localization in rough gold nanoclusters on the graphite surface
- 2007
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Ingår i: JETP Letters. - 0021-3640 .- 1090-6487. ; 86:6, s. 393-397
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Tidskriftsartikel (refereegranskat)abstract
- The results of scanning tunneling spectroscopy of the electronic states of Au nanoclusters on the graphite surface are presented. The tunneling current is found to be different at different points of a rough-surface nano-cluster. The measured differential current-voltage curve of the clusters is nonmonotonic near the Fermi energy, and the tunneling conductance decreases by almost a factor of two as the cluster volume changes from I to 0.1 mm(3). This decrease can be associated with the change in the density of the electronic states near the Fermi energy. The observed features are qualitatively described within the framework of the mechanism of electron localization in disordered systems.
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| 5. |
- Brodin, Gert, et al.
(författare)
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Generation of gravitational radiation in dusty plasmas and supernovae
- 2005
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Ingår i: JETP Letters. - : Pleiades Publishing Ltd. - 0021-3640 .- 1090-6487. ; 81:4, s. 135-139
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Tidskriftsartikel (refereegranskat)abstract
- We present a novel nonlinear mechanism for exciting a gravitational radiation pulse (or a gravitational wave) by dust magnetohydrodynamic (DMHD) waves in dusty astrophysical plasmas. We derive the relevant equations governing the dynamics of nonlinearly coupled DMHD waves and a gravitational wave (GW). The system of equations is used to investigate the generation of a GW by compressional Alfvén waves in a type II supernova. The growth rate of our nonlinear process is estimated, and the results are discussed in the context of the gravitational radiation accompanying supernova explosions.
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| 6. |
- Bulgakov, E.N., et al.
(författare)
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Spin polarization in quantum dots by radiation field with circular polarization
- 2001
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Ingår i: JETP Letters. - : Pleiades Publishing Ltd. - 0021-3640 .- 1090-6487. ; 73:10, s. 505-509
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Tidskriftsartikel (refereegranskat)abstract
- For circular quantum dot (QD), taking into account the Razhba spin-orbit interaction (SOI), an exact energy spectrum is obtained. For a small SOI constant, the eigenfunctions of the QD are found. It is shown that the application of a radiation field with circular polarization removes the Kramers degeneracy of the QD eigenstates. Effective spin polarization of electrons transmitted through the QD owing to a radiation field with circular polarization is demonstrated. © 2001 MAIK "Nauka/Interperiodica".
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| 7. |
- Chernodub, Maxim N., et al.
(författare)
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Spin-Charge Separation and the Pauli Electron
- 2007
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Ingår i: JETP Letters. - 0021-3640 .- 1090-6487. ; 85:8, s. 353-357
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Tidskriftsartikel (refereegranskat)abstract
- The separation between the spin and the charge converts the quantum mechanical Pauli Hamiltonian into the Hamiltonian of the non-Abelian Georgi-Glashow model, which is notorious for its magnetic monopoles and confinement. The independent spin and charge fluctuations both lead to the Faddeev model, suggesting the existence of a deep duality structure and indicating that the fundamental carriers of the spin and charge are knotted solitons.
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| 8. |
- Girshova, E. I, et al.
(författare)
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Enhancement of the Basal-plane Stacking Fault Emission in GaN Planar Nanowire Microcavity
- 2022
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Ingår i: JETP Letters. - : MAIK NAUKA/INTERPERIODICA/SPRINGER. - 0021-3640 .- 1090-6487. ; 115, s. 574-580
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Tidskriftsartikel (refereegranskat)abstract
- We study and compare optical microcavities formed by GaN planar nanowires. Nanostructures with structural defects such as stacking faults and without defects are considered. The behavior of an exciton localized in a stacking fault is considered. Different behavior of the photoluminescence intensity and the photoluminescence decay time is observed for the cases under consideration. Theoretical calculations show the localization of the field at the ends of the structure.
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| 9. |
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| 10. |
- Gogina, A. A., et al.
(författare)
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Adsorption of Na Monolayer on Graphene Covered Pt(111) Substrate
- 2023
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Ingår i: JETP Letters. - 0021-3640 .- 1090-6487. ; 117:2, s. 138-146
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Tidskriftsartikel (refereegranskat)abstract
- Modification of graphene electronic properties via contact with atoms of different kind allows for designing a number of functional post-silicon electronic devices. Specifically, 2D metallic layer formation over graphene is a promising approach to improving the electronic properties of graphene-based systems. In this work we analyse the electronic and spin structure of graphene synthesized on Pt(111) after sodium monolayer adsorption by means of angle-resolved photoemission spectroscopy and ab initio calculations. Here, we show that sodium layer formation leads to a shift of the graphene pi states towards higher binding energies, but the most intriguing property of the studied system is the appearance of a partially spin-polarized Kanji symbol-like feature resembling the graphene Dirac cone in the electronic structure of adsorbed sodium. Our findings reveal that this structure is caused by a strong interaction between Na orbitals and Pt 5d spin-polarized states, where the graphene monolayer between them serves as a mediator of such interaction.
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