We study a possible physical realization of a quantum controlled-NOT gate with the use of two weakly coupled asymmetric quantum dots. Solving the time-dependent Schrödinger equation for the model two-electron sys...
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We study a possible physical realization of a quantum controlled-NOT gate with the use of two weakly coupled asymmetric quantum dots. Solving the time-dependent Schrödinger equation for the model two-electron system, we simulate the infrared-radiation-induced quantum transitions that correspond to basic gate operations. We require the transition probabilities to be close to 1 and optimize the parameters of the nanostructure in order to make the gate operation time as short as possible. In the simulations, we have taken into account the entire energy spectrum, which can be populated by the absorption or emission of the infrared radiation. We discuss the consequences of the existence of many bound two-electron states on the probability of radiative transitions.
Nuclear magnetic resonance (NMR) experiments on single crystals of HgBa2CuO4+δ are presented that identify two distinct temperature-dependent spin susceptibilities: One is due to a spin component that is temperature-...
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Nuclear magnetic resonance (NMR) experiments on single crystals of HgBa2CuO4+δ are presented that identify two distinct temperature-dependent spin susceptibilities: One is due to a spin component that is temperature-dependent above the critical temperature for superconductivity (Tc) and reflects pseudogap behavior; the other is Fermi-liquid-like in that it is temperature independent above Tc and vanishes rapidly below Tc. In addition, we demonstrate the existence of a third spin susceptibility: It is temperature independent at higher temperatures, vanishes at lower temperatures (below T0≠Tc), and changes sign near optimal doping. This susceptibility either arises from the coupling between the two spin components, or it could be given by a distinct third spin component. Recent susceptibility data on single crystals support its presence in most cuprates.
The Bayes approach is arguably the classification method most used in unspecialized applications, thanks to its robustness, simplicity, and interpretability. The main problem here is establishing proper probability va...
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We present the design of the ABCN front-end chip implemented in a CMOS 0.25 μm technology and optimized for short silicon strip detectors as foreseen for the ATLAS Silicon Tracker Upgrade. A primary aim of this proje...
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ISBN:
(纸本)9789290833246
We present the design of the ABCN front-end chip implemented in a CMOS 0.25 μm technology and optimized for short silicon strip detectors as foreseen for the ATLAS Silicon Tracker Upgrade. A primary aim of this project is to develop an ASIC with full functionality required for readout of short silicon strips in the SLHC environment in a cost-effective and proven technology. Design efforts have been focused on optimizing noise and power performance of the front-end circuit for low detector capacitance, minimizing power consumption in digital blocks and on compatibility with new power distribution schemes being developed for future tracker detectors. The architecture of the chip as well as critical and novel design aspects are discussed in the paper. The ABCN ASIC will serve as a basic test vehicle in an extensive program on development of sensors and modules for the ATLAS Silicon Tracker Upgrade.
Electron transport in the plane of a monoatomic metallic layer with non-zero magnetization is considered. The material is represented by a two-dimensional set of disordered potentials which also possess spins aligned ...
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Electron transport in the plane of a monoatomic metallic layer with non-zero magnetization is considered. The material is represented by a two-dimensional set of disordered potentials which also possess spins aligned along one axis but not necessarily oriented in one direction. Such a system can be treated as a two-component alloy. The effective cross-section for conduction electrons has been calculated. The total conductivity is obtained within two-current model.
The main premise of the present study is a change in the attitude of the fusion community regarding the fission power - from perceiving it as an ally of fusion not a competitor. Seeing this, first some basic problems ...
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ISBN:
(纸本)9781617824760
The main premise of the present study is a change in the attitude of the fusion community regarding the fission power - from perceiving it as an ally of fusion not a competitor. Seeing this, first some basic problems of the nuclear power have been sketched and then the question of spent fuel transmutations and its properties in view of energy content. In search for solutions subcritical Fusion-Driven Incinerator systems (FDI) have been considered. The advantage of subcritical systems lies in their remoteness from superprompt criticality. Next the problems of nuclear fusion have been addressed and the ways of solution with use of fission energy contained in actinides of spent nuclear fuel have been proposed. The main positive of that option of fusion power, /thanks to energy release from fissions/, is the prospect of a radical reduction of necessary plasma energy gain Q to levels achievable in much smaller i.e. much more economic devices. No less important advantages of the FDI system are: reduced load of the First Wall (FW) with 14 MeV neutrons and well homogeneous heating distribution. One should not forget that just the radiation damage is one of the main sources of difficulties in fusion technology. Then it has been suggested that one of the most viable incineration concepts is a symbiotic nuclear energy system, consisting of an incinerator of transuranics (Pu, Np and Am) and of a number of co-operating Light Water Reactors (LWRs). Summarising, the concept of actinides incineration in fusion-driven subcritical systems significantly heightens safety of nuclear power systems as a whole. In conclusion, the option of fusion presented herewith as a means to solve the problems inherent to fission based nuclear energy may facilitate the development and then launching of the fusion power.
The diffusive motion of quasi-two-dimensional electron gas through an ultra-thin system of disordered potentials is considered. In such a system, the Fermi sphere splits into a set of independent sheets due to a small...
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The diffusive motion of quasi-two-dimensional electron gas through an ultra-thin system of disordered potentials is considered. In such a system, the Fermi sphere splits into a set of independent sheets due to a small thickness of the system. Each sheet can be seen as an electron subband. Electron transport goes through these subbands independently. The sum of electrical conductivities over the subbands determines the total current, which is calculated for ultra-thin films of cesium. We also present the relation between our approach and the Landauer formalism based on the notion of the transmission coefficient.
In 1969, Roberts introduced proper and unit interval graphs and proved that these classes are equal. Natural generalizations of unit interval graphs called k-length interval graphs were considered in which the number ...
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Electron transport through a disordered two-dimensional array of potentials has been investigated. The resistivity was calculated according to the Faber-Ziman diffraction model, suitably modified for a two-dimensional...
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Electron transport through a disordered two-dimensional array of potentials has been investigated. The resistivity was calculated according to the Faber-Ziman diffraction model, suitably modified for a two-dimensional electron gas. The structure factor is obtained by means of numerical simulations. The pseudopotentials are assumed to be Shaw potentials with appropriate screening. The resistivities of disordered monolayers of alkali metals have been calculated in this model using parameters that allowed us to explain the experimental data for bulk materials.
The purpose of this work was to determine whether the structures of ordered part of novel poly(3,4-ethylenedioxythiophene) PEDOT : OTf (doped with trifluoromethanesulfonate anions) and PEDOT : HSulf (doped with hydrog...
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