Geometric and compositional influences on spin-orbit induced circulating currents in nanostructures

Circulating orbital currents, originating from the spin-orbit interaction, are calculated for semiconductor nanostructures in the shape of spheres, disks, spherical shells and rings for the electron ground state with spin oriented along a symmetry axis. The currents and resulting orbital and spin magnetic moments, which combine to yield the effective electron g factor, are calculated using a recently introduced formalism that allows the relative contributions of different regions of the nanostructure to be identified. For all these spherically or cylindrically symmetric hollow or solid nanostructures, independent of material composition and whether the boundary conditions are hard or soft, the dominant orbital current originates from intermixing of valence band states in the electron ground state, circulates within the nanostructure, and peaks approximately halfway between the center and edge of the nanostructure in the plane perpendicular to the spin orientation. For a specific material composition and confinement character, the confinement energy and orbital moment are determined by a single size-dependent parameter for spherically symmetrical nanostructures, whereas they can be independently tuned for cylindrically symmetric nanostructures.Comment: 22 pages, 20 figure

Spin-orbit-induced circulating currents in a semiconductor nanostructure

Circulating orbital currents produced by the spin-orbit interaction for a single electron spin in a quantum dot are explicitly evaluated at zero magnetic field, along with their effect on the total magnetic moment (spin and orbital) of the electron spin. The currents are dominated by coherent superpositions of the conduction and valence envelope functions of the electronic state, are smoothly varying within the quantum dot, and are peaked roughly halfway between the dot center and edge. Thus the spatial structure of the spin contribution to the magnetic moment (which is peaked at the dot center) differs greatly from the spatial structure of the orbital contribution. Even when the spin and orbital magnetic moments cancel (for $g=0$) the spin can interact strongly with local magnetic fields, e.g. from other spins, which has implications for spin lifetimes and spin manipulation.Comment: 6 pages, 3 figure

g-Factors and diamagnetic coefficients of electrons, holes and excitons in InAs/InP quantum dots

The electron, hole, and exciton g-factors and diamagnetic coefficients have been calculated using envelope-function theory for cylindrical InAs/InP quantum dots in the presence of a magnetic field parallel to the dot symmetry axis. A clear connection is established between the electron g-factor and the amplitude of the those valence-state envelope functions which possess non-zero orbital momentum associated with the envelope function. The dependence of the exciton diamagnetic coefficients on the quantum dot height is found to correlate with the energy dependence of the effective mass. Calculated exciton g-factor and diamagnetic coefficients, constructed from the values associated with the electron and hole constituents of the exciton, match experimental data well, however including the Coulomb interaction between the electron and hole states improves the agreement. Remote-band contributions to the valence-band electronic structure, included perturbatively, reduce the agreement between theory and experiment.Comment: 12 pages, 7 figure

Bibliography for 2020

Knjige, članci i recenzije o arheologiji, povijesti i povijesti umjetnosti Dalmacije do 12. stoljeća za godinu 2020.Books, articles and reviews on the archaeology, history and arthistory of Dalmatia up to the twelfth century for 2020

Odabir biljnih vrsta za uređenje seoskog turističkog gospodarstva

Promjenama načina života te urbanizacijom, drastično se mijenja način uređenja i odabira vrsta u seoskim vrtovima. Vlasnici seoskih turističkih gospodarstava, nastoje zadržati tradicionalne vrijednosti svog kraja i prezentirati ih gostima. Zbog nepoznavanja tradicije ili neprepoznavanja važnosti uređenja okućnice, u tom su segmentu vrlo česte pogreške i pojava kiča. Seosko gospodarsko imanje Kezele smiješteno u selu Šumečani, obiluje brojnim starim drvenim kućama koja se sve više obnavljaju za turizam i u svrhu očuvanja kulturne vrijednosti. U svrhu potpune i kvalitetne obnove potrebno je obnoviti i tradicijske okućnice za što treba istražiti njihov izgled, odabir i način korištenja tradicijskih biljnih vrsta, te ostale elemente tradicijskog vrta poput staza, ograda, vrtnih vrata i vrtnog namještaja. U radu se utvrdilo koje su se biljne vrste tradicionalno koristile u seoskim vrtovima na području Šumečana, inventarizirane su biljne vrste na području seoskog imanja Kezele i okolnih okućnica, a naposljetku je dat prijedlog biljnih vrsta za uređenje seoskog imanja Kezele u skladu s tradicijom kraja. Pregledom arhivske građe te metodom intervjua utvrdilo se koje su biljne vrste nekad bile zastupljene u sklopu seoskih okućnica u Šumečanima. Inventarizirale su se biljne vrste koje se nalaze u sklopu istraţivanog seoskog imanja Kezele, a na temelju literature odredila se njihova taksonomska pripadnost, porijeklo i namjena uzgoja. Iz provedenog istraţivanja vidljivo je da seoski tradicijski vrtovi polako nestaju, uslijed sve veće urbanizacije, te starenja stanovništva. Najzastupljenije biljne svojte su: Vitis vinifera L., Rosa sp., Viola x wittrokiana Gams., Primula vulgaris L., Malus domestica L. i Juglans regia L.. Na svim okućnicama i na seoskom imanju Kezele najzastupljenija je porodica Rosaceae, a ukrasne svojte prevladavaju na svim okućnicama.As the way of living and earning changes, together with urban growth, the way of garden structure and choice of plant species is drastically changed. Owners of countryside family farms try to maintain traditional values of their area and present them to their guests. Lack of knowledge, understanding of local tradition or importance of home gardening often results with poor/trashy exterior decoration. Country family farm Kezele is located in village of Šumećani and is full of old wooden houses, restored for the purpose of tourism and cultural preservation. For the purpose of full and quality restoration, it is also important to restore original home garden, understand how they looked like in the past, to properly select and plant traditional plants and organize other elements of traditional garden like pathways, fences, garden gates and furniture. In my work I will cover plant species traditionally used in country gardens in Šumećani area, catalogue plant species from Kezele estate and surrounding gardens and finally, proposal will be given for choice of gardening plants for Kezele estate in line with the tradition of local area. By searching through old archive materials and interviewing local people, it is going to be determined which plant species were native in past in Šumećani home garden. Plant species from researched Kezele estate werw catalogued, and with help of literature their taxonomy nomenclature, origin and purpose of cultivation were determined. From conducted research, one can see that traditional country gardens are dissapearing, as a result of urbanisation and aging population. The most common plant species are Vitis vinifera L., Rosa sp., Viola x wittrokiana Gams., Primula vulgaris L., Malus domestica L. i Juglans regia L.. In all gardens and on Kezele estate the most common is family Rosaceae and it's decorative varieties are dominating in all gardens

Large asymmetric Stark shift in GaxIn1–xAs/InP/InAsyP1–y composite quantum wells

Strong asymmetric Stark shift in excess of 115 meV of the lowest energy transition has been experimentally observed in composite Ga/sub x/In/sub 1-x/As/InP/InAs/sub y/P/sub 1-y/ quantum-well system. In this structure, we can independently control the confinement of electrons and holes by controlling the strain. The photoexcited electrons and holes are confined in spatially separated regions without the application of an electric field. Due to the large asymmetry in the structure, we observed large blueshifts and redshifts of the absorption edge with an applied electric field. All our measurements agree with the calculations within the framework of the Bir-Pikus strain Hamiltonia

EDUCATION AND THE THEORY OF MEANING

Odgoj je smislena i vrijednosna funkcija društva – važna u životu čovjeka. Teorija smisla je pogodna za objašnjavanje fenomena odgoja. Autor slijedi defi niciju smisla prema Šešiću (1977): smisao je promjenjiva, razvojna ili procesualna pojava. Dakle, smisao je prije svega relacija ili odnos. Dva su bitna čimbenika smisla: nositelj smisla i sam smisao. Nositelji (be)smisla mogu biti sve pojave u društvu i čovjekovu životu. Izdvojene su ove kategorije smisla: smisao organiziranosti, osmišljenosti, usmjerenosti, svrhovitosti, funkcionalnosti i smisao vrijednosti. Autor razmatra odnos između teorija čovjekova života i smisla. Odgoj ima važnu ulogu u čovjekovu životu. Nositelji smisla odgoja mogu biti: odgojni ideal, ciljevi i zadaci odgoja; faktori odgoja; subjekti odgoja; organizacijski modeli odgoja; oblici i sredstva odgoja i evaluacijski instrumenti za prosuđivanje smisla i učinkovitosti odgoja. Na primjeru sedam povijesno-epohalnih i svakodnevnih dvojbi konstruiran je teorijski model za raspravu o smislu odgoja. Autor je razradio i neke aspekte metodologije istraživanja smisla života i odgoja, posebno hermeneutičkofenomenologijsku paradigmu i narativnu analizu.The Function of education in society is a meaningful and a valuable one – it is important in an individual’s life. The theory of meaning is provides a very good explanation of the education phenomenon. The author draws upon the meaning theory according to Šešić (1997): meaning is a changeable, developmental or processible phenomenon. Hence, meaning is in the fi rst place a relation or a relationship. There are two important factors of meaning: the meaning holder and the meaning itself. Meaning(lessness) holders can be all the phenomena in a society or an individual’s life. The following meaning categories are singled out: the meanings of being organized, rational approach, direction, purposefulness, functionality and the meaning of value. The author analyzes the relationship between the theories of human lifeand meaning. Education has an important role in a person’s life. Meaning holders include the following: educational ideal, education goals and tasks; education factors; the subjects of education; organisational models of education; education types and instruments as well as evaluation instruments for the assessment of education meaning and effectiveness. On the example of seven historic-epochal and everyday doubts a theoretical model was constructed for the discussion on the meaning of education. The author has also developed some aspects of the methodology of studying the meaning of life and education, especially the hermeneutic-phenomenological paradigm