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.
Feature tracking in large data sets is traditionally an off-line, batch processing operation while virtual reality typically focuses on highly interactive tasks and applications. This paper presents an approach that u...
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New experimental data are presented on the gel electrophoresis of DNA. Experiment was made for molecules of length 173 kbp, in 1 percent agarose gel, in TAB 1x buffer and the field intensity between 5 and 9V/cm. The r...
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New experimental data are presented on the gel electrophoresis of DNA. Experiment was made for molecules of length 173 kbp, in 1 percent agarose gel, in TAB 1x buffer and the field intensity between 5 and 9V/cm. The results are compared with our computer simulations, performed within the repton model of Duke and Rubinstein. The ranges of field and molecule length are determined, where the geometration effect appears. We investigate also the field dependence of the velocity and the diffusion coefficient at the border of the geometration regime.
Recently, a continuous dynamics was proposed to simulate dynamics of interpersonal relations in a society represented by a fully connected graph. The final state of such a society was found to be identical with the so...
Recently, a continuous dynamics was proposed to simulate dynamics of interpersonal relations in a society represented by a fully connected graph. The final state of such a society was found to be identical with the so‐called Heider balance (HB), where the society is divided into two mutually hostile groups. In the continuous model, a polarization of opinions was found in HB. Here we demonstrate that the polarization occurs also in Barabási‐Albert networks, where the Heider balance is not necessarily present. In the second part of this work we demonstrate the results of our formalism, when applied to reference examples: the Southern women and the Zachary club.
The noise of a fast charge sensitive amplifier (CSA) with an input MOS transistor working in moderate inversion region is discussed. The MOS transistor operation in moderate inversion region becomes especially importa...
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The noise of a fast charge sensitive amplifier (CSA) with an input MOS transistor working in moderate inversion region is discussed. The MOS transistor operation in moderate inversion region becomes especially important in multichannel readout systems, where limited power dissipation is required. The ENC of a CSA followed by a fast shaper is usually dominated by the thermal noise of the input MOS transistor. We perform the noise minimization of such CSA, searching for an optimum input transistor width. The analyses are done using a simplified EKV model and are compared to HSPICE simulations with BSIM3v3 model. We consider several CMOS technology generations with minimum transistor gate length ranging from 0.13 mum to 0.8 mum. We study the sensitivity of ENC to the input transistor width and propose a simple formula to estimate the optimum transistor width, which is valid in a wide range of the input transistor current density
We investigate magnetic properties of a two-dimensional periodic structure with Ising spins and antiferromagnetic nearest-neighbor interaction. The structure is topologically equivalent to the Archimedean (3,122) latt...
We investigate magnetic properties of a two-dimensional periodic structure with Ising spins and antiferromagnetic nearest-neighbor interaction. The structure is topologically equivalent to the Archimedean (3,122) lattice. The ground state energy is degenerate. In some ground states, the spin structure is translationally invariant, with the same configuration in each unit cell. Numerical results are reported on specific heat and static magnetic susceptibility against temperature. Both quantities show maxima at temperature T>0. They reveal some sensitivity on the initial state in temperatures where the Edwards–Anderson order parameter is positive. For zero temperature and low frequency of the applied field, the magnetic losses are negligible. However, the magnetization curve displays some erratic behavior due to the metastable states.
An electron wave packet formed in a semiconductor heterostructure containing a quantum well covered by a metal surface is considered. It is demonstrated that the potential of the charge induced by the electron wave pa...
An electron wave packet formed in a semiconductor heterostructure containing a quantum well covered by a metal surface is considered. It is demonstrated that the potential of the charge induced by the electron wave packet on the conducting surface possesses a component of lateral confinement stabilizing its shape. The existence of electron solitons, i.e., running electron wave packets propagating without changing their shape, is demonstrated. In the scattering phenomena, the electron interacting with the induced charge tends to behave like a classical particle with the backscattering probability approaching a step dependence on the incident momentum as the distance from the metal surface is decreased. This effect enhances the ballistic character of transport for fast electrons and facilitates the trapping of slowly moving electrons.
57Fe Mössbauer spectra were recorded on the σ — phase of FexV1−x, x = 0.52 and 0.60 and of FexCr1−x, x = 0.51 and 0.532 in the temperature range 4.3 to 294 K. For the Fe‐V samples, from the temperature depende...
57Fe Mössbauer spectra were recorded on the σ — phase of FexV1−x, x = 0.52 and 0.60 and of FexCr1−x, x = 0.51 and 0.532 in the temperature range 4.3 to 294 K. For the Fe‐V samples, from the temperature dependence of the average centre shift Debye temperatures θD = 457 ± 15 K and 437 ± 30 K were determined for x = 0.52 and 0.60, respectively. Values of θD = 488 ± 15 K and 459 ± 15 K were derived for the Fe‐Cr samples with x = 0.51 and 0.532, respectively. The values are compared with the ones obtained for isostructural Fe‐Cr compounds from previous investigations.
This work has focused on the design and finite element modeling of a MEMS cantilever beam for biosensor applications. The stress induced on gold surface with polysilicon piezoresistive sensing is demonstrated. In prin...
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We study field-driven dynamics of spins with antiferromagnetic interactions along the links of a complex substrate geometry, which is modeled by graphs of a controlled connectivity distribution. The magnetization reve...
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We study field-driven dynamics of spins with antiferromagnetic interactions along the links of a complex substrate geometry, which is modeled by graphs of a controlled connectivity distribution. The magnetization reversal occurs in avalanches of spin flips, which are pinned by the topological constraints of the underlying graph. The hysteresis loop and avalanche sizes are analyzed and classified in terms of the graph’s connectivity and clustering. The results are relevant for magnets with a hierarchical spatial inhomogeneity and for design of nanoscale magnetic devices.
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