Conductance of a double quantum dot with correlation-induced wave function renormalization

The zero-temperature conductance of diatomic molecule, modelled as a correlated double quantum dot attached to noninteracting leads is investigated. We utilize the Rejec-Ramsak formulas, relating the linear-response conductance to the ground-state energy dependence on magnetic flux within the framework of EDABI method, which combines exact diagonalization with ab initio calculations. The single-particle basis renormalization leads to a strong particle-hole asymmetry, of the conductance spectrum, absent in a standard parametrized model study. We also show, that the coupling to leads V=0.5t (t is the hopping integral) may provide the possibility for interatomic distance manipulation due to the molecule instability.Comment: Presented on the The International Conference on Strongly Correlated Electron Systems SCES'05, July 26-30th 2005, Vienna, Austria. An abbreviated version will appear in Physica

Analiza pravnih vidikov odvzema premoženja nezakonitega izvora

Purpose: The aim of the study was to analyse the legal aspects of asset recovery in Slovenia through a five-stage asset-recovery process: financial investigationfreezing or seizure of assetsconfiscationenforcement of the confiscation orderand asset disposal. Design/Methods/Approach: EU and Slovenian legislation in the area of illegal asset recovery was analysed and compared. Using legal analysis, gaps and inconsistences were discovered and discussed. Findings: The Slovenian legal order provides relevant bodies with several avenues to recover ‘proceeds’ and illegally acquired assets. There is the traditional confiscation of proceeds, in personam confiscation in criminal proceedings, extended confiscation in criminal proceedings, and civil forfeiture pursuant to the Forfeiture of Assets of Illegal Origin Act. One problem is the related provisions are dispersed across both substantive and procedural law. Another problem is that some provisions are formulated in such a way that makes them impossible to apply in practice. It would be necessary to introduce a category of financial investigation in criminal proceedings. It is inappropriate that financial investigations are carried out under the provisions of civil law. Financial investigation must, therefore, become an essential part of all police criminal investigations of relevant offences, and holds the potential to generate proceeds. However, at the same time, law enforcement authorities must obtain a clear mandate that in the particular conditions they may investigate all assets of a suspect and not simply the concrete proceeds of crime. Practical Implications: The study findings are useful for preparing systemic changes in relation to the seizure of assets of illegal origin, also because the changes can be used to help establish an efficient way of organising the work of state bodies in this area. Originality/Value: The purpose of the paper is to comprehensively analyse all aspects of the seizure of assets of illegal origin. The results of the analysis substantially complement existing knowledge in the analysed field.Namen prispevka: Namen študije je analizirati pravne vidike odvzema premoženja nezakonitega izvora v Sloveniji skozi prizmo petstopenjskega procesa odvzema nezakonitega premoženja: finančna preiskava, zamrznitev oziroma zavarovanje premoženja, odvzem premoženja, izvršitev odločbe o odvzemu ter upravljanja z odvzetim premoženjem. Metode: V prispevku smo s pomočjo pravne analize primerjali evropsko in slovensko zakonodajo na področju odvzema premoženja nezakonitega izvora. S pomočjo primerjave pravnih dokumentov smo ocenili razkorake in nedorečenosti med želeno in dejansko ureditvijo tega področja v Sloveniji. Ugotovitve: Slovenski pravni red pristojnim organom ponuja več možnosti odvzema premoženja nezakonitega izvora. Uporabijo lahko klasični odvzem premoženjskih koristi v okviru kazenskega postopka, razširjeni odvzem po kazenski zakonodaji ter civilni odvzem preko tožbe v skladu z zakonom o odvzemu premoženja nezakonitega izvora. V analizi smo ugotovili težave pri jasnosti materialnih določb materialnega in procesnega prava. Nadaljnja težava je, da so nekatere določbe v slovenski zakonodaji oblikovane tako, da jih ni mogoče izvajati v praksi. Avtorji menimo, da bi bilo nujno opredeliti finančno preiskavo v okviru kazenske zakonodaje. Ni primerno, da se finančna preiskava izvaja po določbah civilnega prava. Poleg tega mora finančna preiskava postati ključni del vseh kriminalističnih preiskav kaznivih dejanj, kjer je mogoče uveljavljati odvzem premoženja nezakonitega izvora, pri tem pa mora biti v zakonu nedvoumno zapisan mandat in odgovornosti za izvedbo finančne preiskave. Praktična uporabnost: Ugotovitve študije so koristne pri pripravi sistemskih sprememb na področju zasega premoženja nezakonitega izvora, mogoče pa jih je uporabiti tudi pri vzpostavitvi učinkovite organizacije dela državnih organov na analiziranem območju. Izvirnost/pomembnost prispevka: Namen prispevka je celostno analizirati vse vidike zasega premoženja nezakonitega izvora. Rezultati analize bistveno dopolnjujejo obstoječe znanje na analiziranem področju

Entanglement between static and flying qubits in quantum wires

A weakly bound electron in a semiconductor quantum wire is shown to become entangled with an itinerant electron via the coulomb interaction. The degree of entanglement and its variation with energy of the injected electron, may be tuned by choice of spin and initial momentum. Full entanglement is achieved close to energies where there are spin-dependent resonances. Possible realisations of related device structures are discussed

Entanglement and transport through correlated quantum dot

We study quantum entanglement in a single-level quantum dot in the linear-response regime. The results show, that the maximal quantum value of the conductance 2e^2/h not always match the maximal entanglement. The pairwise entanglement between the quantum dot and the nearest atom of the lead is also analyzed by utilizing the Wootters formula for charge and spin degrees of freedom separately. The coexistence of zero concurrence and the maximal conductance is observed for low values of the dot-lead hybridization. Moreover, the pairwise concurrence vanish simultaneously for charge and spin degrees of freedom, when the Kondo resonance is present in the system. The values of a Kondo temperature, corresponding to the zero-concurrence boundary, are also provided.Comment: Presented on the International Conference "Nanoelectronics '06", 7-8 January 2006, Lancaster, U