共查询到20条相似文献,搜索用时 15 毫秒
1.
A. V. Tsukanov 《Russian Microelectronics》2011,40(1):8-16
In the second part of our review, we focus on such urgent problems of modern physics as the use of superconductors in quantum
informatics and coherent control of the state of mesoscopic systems. 相似文献
2.
The high-frequency properties of superconductors are reviewed, including the London, Pippard, and Mattis-Bardeen surface impedance, and techniques for measuring and separating losses are discussed. Residual resistance mechanisms are described and evaluated, including high field effects. The state of knowledge is shown to be adequate for engineering design. Applications of superconducting resonators and lines to filters, tuners, oscillators, amplifiers and mixers, transmission lines, antennas, optical and radiation detection, and materials research are discussed. 相似文献
3.
We consider one- and two-qubit operations on charge qubits that represent double quantum dots with one electron in each of them. The dots are formed inside a high-Q semiconductor cavity (disk, toroidal, or spherical) in the antinodes of one of its optical eigenmodes; the frequencies of the transitions between the ground (logic) and excited (auxiliary) states of the discrete electron spectrum in quantum dots are close to the frequency of this mode. The precise tuning of the transition frequency is performed by applying an electric potential on the qubit control gate. Within the model of qubits coherently interacting with a cavity quantum field, a few methods for controlling their states are developed. In particular, we propose different variants for implementing two-qubit CNOT and CZ gates and generating qubit entangled states. By the example of a micro-disk cavity, we calculate the operating characteristics that ensure a high rate of quantum gate implementation. 相似文献
4.
A theoretical investigation is presented into the coherent dynamics of a charge qubit in the form of two tunnel-coupled quantum dots containing a single electron, with the logic states represented by electron orbitals localized at the quantum dots. Analytical expressions are derived for the evolution of a one-or two-qubit system in an applied field. The system and field parameters are evaluated in terms of performing basic one-qubit operations. The possibility is explored for implementing the CNOT operation in a two-qubit system driven by error-free or error-prone control pulses. 相似文献
5.
A. N. Voron’ko 《Semiconductors》2008,42(6):655-661
The electron energy spectrum of the singly ionized pair of phosphorus donors in silicon, P 2 + , is calculated numerically, taking into account the sixfold degeneracy of the conduction band. The envelopes of wave functions of different states are determined. The results are used to simulate operations with the P 2 + /Si-based charge qubits via exposure to laser pulses. 相似文献
6.
A. V. Tsukanov 《Russian Microelectronics》2016,45(2):77-90
Techniques for fabricating nanomechanical diamond systems and their use in modern micro- and nanoelectronics are reviewed. The primary focus is the experimental techniques for controlling the quantum state of nitrogen-vacancy centers in diamond by mechanical actions. Optimization of the working characteristics of diamond resonators is discussed. 相似文献
7.
A. V. Tsukanov 《Russian Microelectronics》2012,41(3):145-161
The spectral and coherent properties of nitrogen-vacancy (NV) centers in diamond are described, together with the techniques
used for their experimental investigation. Particular attention is given to recently developed methods of initialization and
spin-state identification for a single NV center or a spin system based on an NV center. Both electronic and nuclear spin
are considered. Active and passive methods of lengthening the relaxation and phase-coherence times are discussed. 相似文献
8.
9.
A. V. Tsukanov 《Russian Microelectronics》2013,42(6):325-346
The main types, fabrication technologies, and physical characteristics of photonic molecules are reviewed. The spectra and spatial configurations of molecular eigenmodes are analyzed within the tight-binding model. Experimental methods for studying the properties of photonic molecules and controlling their states with the use of various external devices are described in detail. 相似文献
10.
Analytical solutions to drain current, depletion and inversion charges for MOSFETs with an ideally abrupt retrograde doping profile in the channel are derived based on the charge sheet model. The validity of the analytical solutions is confirmed by comparing the modeling results with simulation data obtained using numerical calculations; the modeling and simulation results are in excellent agreement. It is shown that the inclusion of an intrinsic surface layer in the channel causes a voltage shift in the drain current, in accordance with experimental observations. For the depletion charge, an analytical expression principally identical to that for the uniformly doped body case is found with a simple replacement of the surface potential, ψs, by the potential at the interface between the intrinsic surface layer and the doped substrate, ψξ. 相似文献
11.
12.
Kleiner R. Koelle D. Ludwig F. Clarke J. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》2004,92(10):1534-1548
Superconducting quantum interference devices (SQUIDs) are sensitive detectors of magnetic flux. A SQUID consists of a superconducting loop interrupted by either one or two Josephson junctions for the RF or dc SQUID, respectively. Low transition temperature (T/sub c/) SQUIDs are fabricated from thin films of niobium. Immersed in liquid helium at 4.2 K, their flux noise is typically 10/sup -6//spl Phi//sub 0/ Hz/sup -1/2/, where /spl Phi//sub 0//spl equiv/h/2e is the flux quantum. High-T/sub c/ SQUIDs are fabricated from thin films of YBa/sub 2/Cu/sub 3/O/sub 7-x/, and are generally operated in liquid nitrogen at 77 K. Inductively coupled to an appropriate input circuit, SQUIDs measure a variety of physical quantities, including magnetic field, magnetic field gradient, voltage, and magnetic susceptibility. Systems are available for detecting magnetic signals from the brain, measuring the magnetic susceptibility of materials and geophysical core samples, magnetocardiography and nondestructive evaluation. SQUID "microscopes" detect magnetic nanoparticles attached to pathogens in an immunoassay technique and locate faults in semiconductor packages. A SQUID amplifier with an integrated resonant microstrip is within a factor of two of the quantum limit at 0.5 GHz and will be used in a search for axions. High-resolution magnetic resonance images are obtained at frequencies of a few kilohertz with a SQUID-based detector. 相似文献
13.
Shams-Zadeh-Amiri A.M. Safavi-Naeini S. Chaudhuri S.K. Sabry R. 《Microwave Theory and Techniques》2002,50(11):2480-2490
Based on the reciprocity theorem, the reaction concept in electromagnetic theory is generalized to the cases where both surface electric and magnetic currents overlap across boundaries, i.e., neither the E-field, nor H-field meets the continuity conditions. An improved systematic method is then developed to obtain unrestricted variational expressions in a cavity resonator for which the tangential components of the trial fields can be discontinuous across its interior boundaries. 相似文献
14.
《Solid-State Circuits, IEEE Journal of》1975,10(6):371-379
Describes a technique for performing A/D conversion compatibly with standard single-channel MOS technology. The use of a binary weighted capacitor array to perform a high-speed, successive approximation conversion is discussed. The technique provides an inherent sample/hold function and can accept both polarities of inputs with a single positive reference. The factors limiting the accuracy and conversion rate of the technique are considered analytically. Experimental results from a monolithic prototype are presented; a resolution of 10 bits was achieved with a conversion time of 23 /spl mu/s. The estimated die size for a completely monolithic version is 8000 mil/SUP 2/. 相似文献
15.
In this review, we generalize and systematize the experimental data of the past few years concerning the implementation of solid-state photonic structures based on synthetic diamond materials. We list the physical properties and performances of the available devices and describe the technologies for their fabrication. The aim of the review is to establish whether the quality of the available quantum network elements, including various waveguide structures and microcavities interacting with the color centers, meets the concept of a solid-state photonic chip. 相似文献
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17.
A. V. Tsukanov 《Russian Microelectronics》2014,43(3):165-180
The paper continues to consider hybrid systems that are based on quantum dots (QDs) integrated into solid-state optical structures—photonic molecules (PMs). It presents the main results that are directly or indirectly related to processing quantum information by the above systems, in particular, by an elementary cell of a solid-state quantum register—a QD coherently interacting with delocalized photonic modes. The properties and the manufacturing technology of large PMs—coupled resonator optical waveguides (CROWs) serving as transport channels during the control of qubits—are considered in detail. 相似文献
18.
《Optical Fiber Technology》2007,13(4):281-290
In this paper, the authors present a detailed theoretical and numerical analysis of an in-fiber photonic device based on micro-structured fiber Bragg gratings for sensing and telecommunication applications. The investigated structure consists in a fiber Bragg grating with a localized stripping of the cladding layer. The thinning of the cladding layer changes the core propagation features and thus it induces a phase delay on the guided mode, leading to the formation of a defect state inside the original grating band-gap in agreement with the phase-shift grating theory. The behaviour of the defect state is ruled by three main parameters identified in the length and depth of the stripped region and the surrounding refractive index. This special characteristic leads to the possibility to realize a new class of active and passive photonic devices. In particular, here, the theoretical and numerical analysis of the spectral behaviour exhibited by the device and its dependence on the perturbation features have been carried out. Particular emphasis has been focused on the effect of the SRI on the spectral response, providing an exhaustive analysis of the potentiality of the device both for sensing and telecommunication applications. In addition, the investigation of standard uniform and strong fiber Bragg gratings has been carried out. Finally, the case of real devices realized by wet chemical etching in hydrofluoric acid solutions was analysed and a spectral equivalence was found to extend the design rules identified for the ideal case. 相似文献
19.
Recording fetal and adult magnetocardiograms using high-temperature Superconducting quantum interference device gradiometers 总被引:1,自引:0,他引:1
Yi Zhang Wolters N. Lomparski D. Zander W. Banzet M. Krause H.-J. van Leeuwen P. 《Applied Superconductivity, IEEE Transactions on》2003,13(4):3862-3866
In this paper, we analyze the influence of the superconducting quantum interference device (SQUID) gradiometer baseline on the recording of magnetocardiographic measurements. The magnetometers consist of high-temperature superconducting radio-frequency SQUIDs fabricated from YBaCuO thin films, and a substrate resonator which serves as tank circuit. The gradiometers are formed using two or three such magnetometers with individual readouts in electronic difference. We have compared the measurement results using a magnetometer and first- and second-order gradiometers with different baselines. In a standard magnetically shielded room, we found not only an increasing signal-to-noise ratio in adult magnetocardiographic measurements, but also a decreasing distortion of the magnetic field map with increasing baseline of the gradiometer. Using a first-order gradiometer with an ultralong baseline of 18 cm, we have successfully measured the heart signal of a fetus in real time. 相似文献
20.
Bogineni K. Ludwig R. Mogensen P. Nandlall V. Vucetic V. Yi B.K. Zvonar Z. 《Communications Magazine, IEEE》2009,47(2):40-43
Current cellular networks based on Third Generation Partnership Project (3GPP) and 3GPP2 technologies provide evolution from circuit-switched technologies, originally developed for voice communications, to packetswitched technologies. Next-generation networks need to deliver IP-based services (voice, video, multimedia, data, etc.) for all kinds of user terminals while moving between fixed (fiber, DSL, cable) and wireless (3GPP-based, 3GPP2-based, IEEE-based) access technologies, and roaming between various operator networks. Users expect the network to originate, terminate, and maintain a session while the user is moving and roaming. Services have to be delivered to users based on serving network functionality (quality of service [QoS], bandwidth, etc.), availability, and user preferences. The network and users must be protected through various authentication, encryption, and other security mechanisms at the access, network, and application layers. Mobility has to be provided through coordinated link, network, and application layer mobility mechanisms that ensure user expectations of service performance are met. Requirements on the radio technology include improved performance as well as reduced system and device complexity. 3GPP Release 8 specifies the architecture to meet the above requirements. 相似文献