利用射频反射技术从硅基量子计算机中读取自旋信息

导论将量子计算的想法变成实用的技术是当前科技领域的一大挑战,利用变化的电磁场来操控硅晶体管中的电子,是一个较为可能的实施方法。在本题中,我们尝试利用射频反射法和单电子晶体管(以下简称SET)从硅基量子计算原型机读出量子比特。本文第一部分与第二部分讨论无线电波在电缆中的传输,第三部分探究了无线电波的反射条件,第四部分介绍了SET,第五部分与第六部分介绍了射频反射技术以及优化方法。     

一种新型的单电子A/D转换器

传统的A/D转换器结构复杂，利用一种改进的V-PADOX工艺可以制成性能均匀的互补的单电子 晶体管，工艺重复性好.用互补SET对结构实现了多阈值周期性传输功能，这可以用来简化A/ D转换电路.提出了一种利用该互补SET对结构实现的新型3位A/D转换器，具有结构简单、速 度快、功耗低等优点. 关键词： 库仑振荡 A/D转换器 互补单电子晶体管结构     

基于库仑阻塞原理的多值存储器

设计了一种基于库仑阻塞原理的新型单电子多值存储器.器件包括两个多隧穿结结构和一个单电子晶体管，其中单电子晶体管起到一个静电计的作用来实现数据的读取.两个隧穿结库仑阻塞区域的大小不同使得器件具有三个稳定的存储状态.利用这个原理可以制备出多值的动态随机存储器和非挥发性的随机存储器.这种低功耗的单电子多值存储器可以实现信息的超高密度存储. 关键词： 库仑阻塞 单电子晶体管     

纳米器件的制备、表征及其应用

利用建立的常规光刻法的纳米加工工艺系统，研制碳纳米管晶体管，单电子晶体管和单电子晶体集成的纳米器件，研制出了90K的单电子晶体管，实现了两单电子晶体管的电容耦合集成，多个单电子晶体管的串联集成以及单电子晶体管与传统器件的集成。     

单粒子瞬变中的双极放大效应研究

采用三维数值模拟的方法对比研究了单个NMOS晶体管和反相器链中的单粒子瞬变（single event transient,SET）电流脉冲,发现深亚微米工艺下双极放大电流在单管的SET电流脉冲中占主要成分,而在反相器链的SET模拟中不明显,分析二者的区别解释了源/体结偏压的形成过程和放大机理,并证明了双极放大效应受源/体结偏压影响的结论.在此基础上分析了NMOS管中源极的正向电流及其机理,发现台阶区的源极正向电流主要是由扩散作用形成的. 关键词： 单粒子瞬变 双极放大 混合模拟 台阶区电流     

集成单电子晶体管的研究动态

随着微电子器件集成度的提高，芯片上的功能元件尺寸不断减小．国外（如日本东芝公司）已建立０－１μｍ生产线，国内也正研制０－３５μｍ的集成电路．但进一步减小功能元件尺寸的更高集成度的芯片的性能将因量子涨落和散热等问题而非常不稳定，解决这些问题的出路在于选择功耗低并能抑制多种涨落的单电子晶体管．单电子晶体管因它的体积小、无引线集成和极低的操作功率等特点，其高度集成化可远远超越目前大规模集成化的极限并达到海森伯不确定原理设定的极限，是将来不可被取代的新型器件．单电子晶体管由一个量子点和两个分别与源和漏耦…     

单电子晶体管-金属氧化物半导体场效应晶体管多峰值负微分电阻器件

传统的共振隧穿二极管的多峰值负微分电阻器件的峰值数目受到限制，由单电子器件和传统的金属氧化物半导体场效应晶体管(MOSFET)器件组成的多峰值负微分电阻器件在原理上具有无穷多个峰值，并且MOSFET使单电子晶体管(SET)的峰值和谷值电流大小受其源漏电压的影响减小.利用这种多峰值负微分电阻器件实现了多值存储器，该存储器原理上是无穷多值的.并且利用它的折叠的I-V特性，实现了一个4位的Flash A/D转换器，与传统的Flash A/D转换器相比，SET-MOSFET的A/D转换器大大地简化了电路. 关键词： 库仑阻塞 库仑振荡 负微分电阻 多值存储器     

固态量子比特的量子测量

文章介绍了作者用介观输运器件[如量子点接触（QPC）或单电子晶体管（SET）]测量固态量子比特的原理和特性，特别着重地介绍了作者最近在处理被测量子比特和介观测量仪器之间的关联方面的新进展。     

应用光学——光学系统设计指南 第十六章 光电探测器和热探测器

16.2.3 电子倍增和光电倍增管(MPT) 为了测量和探测的需要,光电管的输出常需要加以放大。毫无疑问,这种放大会增加信号的噪声,不过噪声究竟增加多少则取决于放大方法(见第16.2.4节)。电子倍增是噪声比较低的放大方法,因此往往常用     

基于无噪声放大的精密测量增强

随着精密测量的发展,量子噪声已经成为精密测量中的重要噪声来源。借助光场的压缩、量子纠缠等非经典特性的测量手段突破量子噪声极限,从而提高测量精度;另一方面,无噪声放大技术可以实现信号的无噪声放大,从而提高测量的信噪比。本文结合压缩态及无噪声放大技术的优势,实现了一种基于无噪声放大的量子精密测量增强方案,与经典测量相比,信噪比增强到2.00倍。     

Effect of the electromagnetic environment on the single electron transistor

The influence of envirommental impedances on tunneling rates in a single electron transistor circuit is investigated. Effects of the finite gate capacitance and of stray capacitances at the tunnel junctions are considered. For the case of a low impedance environment the electron tunneling rates reduce to the so-called global rule rate while for a high impedance environment a modification of the so-called local rule rate arises from the stray capacitances. Special emphasis is given to the dependence of the current on the gate voltage which determines the sensitivity of electrometers based on the transistor setup. It is found that a higher sensitivity of the electrometer can be achieved by means of asymmetric transistors.     

Quantum-limited sensitivity of single-electron-transistor-based displacement detectors

We consider a model of a quantum-mechanical resonator capacitively coupled to a single electron transistor (SET). The tunnel current in the SET is modulated by the vibrations of the resonator, and thus the system operates as a displacement detector. We analyze the effect of the backaction noise of charge fluctuations in the SET onto the dynamics of the resonator and evaluate the displacement sensitivity of the system. The relation between the "classical" and "quantum" parts of the SET charge noise and their effect on the measured system are also discussed.     

Active light noise filter by a differential operation

A method for an active light noise filter is proposed by using two identical light receivers. They work as a differential electrometer by a common mode connection. Therefore, only an output of a laser light incident upon one receiver can be obtained as a signal. It was found from the experiment that the light noise was reduced to about 0.6% in the usual light room and further the signal to noise ratio was improved up to 30 times at least as compared to a usual light shielding method. The method can then be effectively used under a well-lighted room such as a factory without noise light shielding cover.     

Radio-frequency Bloch-transistor electrometer

A quantum electrometer is proposed which is based on charge modulation of the Josephson supercurrent in the Bloch transistor inserted in a superconducting ring. As this ring is inductively coupled to a high- Q resonance tank circuit, the variations of the charge on the transistor island are converted into variations of amplitude and phase of oscillations in the tank. These variations are amplified and then detected. At sufficiently low temperature of the tank the device sensitivity is determined by the energy resolution of the amplifier, that can be reduced down to the standard quantum limit of 1 / 2Planck's over 2pi. A "back-action-evading" scheme of subquantum limit measurements is proposed.     

A simple tandel electrometer circuit

A simple electrometer circuit is described, which makes use of two TANDELs connected in a bridge type circuit. The results show that an input resistance of 10¹² ohms can easily be obtained in a simple circuit, which is resistant to input voltage overloading and mechanical shocks. The circuit may be used as a simple direct reading electrometer having a sensitivity of about 1 V of the d-c input signal for full scale deflection. A satisfactory performace was found in the whole range of ambient temperatures used for testing, i.e. from 0°C to 40°C.This paper was presented at the Space Radio Communication Conference in Geneva on November 7, 1963.     

Noise properties of a NMR transceiver coil array

The use of multiple radiofrequency (RF) surface coil elements has applications in both fast parallel imaging and conventional imaging techniques. Through implementation of a simple magnetic decoupling network, 50 Omega matching can be achieved in both the transmitter and receiver chains, enabling the use of conventional RF power amplifiers and preamplifiers for transceive applications. Unlike phased array coil arrangements using low impedance preamplifiers for decoupling, the noise correlation between 50 Omega coils decoupled with discrete components has not been characterized. We have measured the dependence of coil quality factor (Q-factor) and noise correlation on coil separation and shown these quantities to be consistent with theoretical arguments, at least at 4 T (170 MHz). Our results suggest that a coil system for transmission and reception of NMR signals with 50 Omega coils can be built to take advantage of all the benefits of conventional array coils and with the added advantages of using conventional amplifiers.     

HIRFL注入器高频腔体与高频机的匹配

 叙述了兰州重离子加速器注入器(SFC)高频系统的200 kW高频机与高频腔体的功率匹配,匹配测量系统的工作原理,以及对匹配系统的改进和完善,并对高频腔体的输入阻抗和耦合电容进行了计算。为提高高频系统的稳定性和可靠性,对影响高频功率传输和D电压提高的问题进行了深入的研究和改进。采用矢量阻抗仪冷态测量腔体匹配阻抗的方法和一些相应的技术和措施,用矢量电压表动态测量功率输出级的相位差,判断D电路是否工作在匹配状态,从而使SFC的D电压由原来的50~65 kV（不稳定）提高到稳定工作的105 kV,改善了SFC的工作状态和保证了SFC的高效运行。     

A 385–500 GHz SIDEBAND-SEPARATING (2SB) SIS MIXER BASED ON A WAVEGUIDE SPLIT-BLOCK COUPLER

We have developed a 385–500 GHz sideband-separating (2SB) mixer, which is based on a waveguide split-block coupler at the edge of the H-plane of the 508 μm × 254 μm (WR 2.0) waveguide, for the Atacama Large Millimeter/submillimeter Array (ALMA). An RF/LO coupler, which contains an RF quadrature hybrid, two LO couplers, and an in-phase power divider, was designed with the issue of mechanical tolerance taken into account. The RF/LO coupler was measured optically with a microscope and electrically with a submillimeter vector network analyzer. The image rejection ratio (IRR) and the single-sideband (SSB) noise temperature of the receiver using the RF/LO coupler have also been measured. The IRR was found to be larger than 8 dB and typically ∼ 12 dB in the 385–500 GHz band. The SSB noise temperature of this receiver is 80 K at the band center, which corresponds to 4 times the quantum noise limit (hf/k) in SSB, and 250 K at the band edges. An erratum to this article can be found at