单电子晶体管(SET)及其应用

当电子器件的尺寸接近纳米尺度时，量子效应对器件工作的影响变得格外重要，就需要采用具有新机理的晶体管结构，单电子晶体管（SET）就是其中一个典型的结构，文中对比传统晶体管（MOSFET）的工作原理，分析了单电子晶体管SET的工作机理，简要概述了SET的一些应用。     

Nanometre-scale displacement sensing using a single electron transistor

It has been a long-standing goal to detect the effects of quantum mechanics on a macroscopic mechanical oscillator. Position measurements of an oscillator are ultimately limited by quantum mechanics, where 'zero-point motion' fluctuations in the quantum ground state combine with the uncertainty relation to yield a lower limit on the measured average displacement. Development of a position transducer, integrated with a mechanical resonator, that can approach this limit could have important applications in the detection of very weak forces, for example in magnetic resonance force microscopy and a variety of other precision experiments. One implementation that might allow near quantum-limited sensitivity is to use a single electron transistor (SET) as a displacement sensor: the exquisite charge sensitivity of the SET at cryogenic temperatures is exploited to measure motion by capacitively coupling it to the mechanical resonator. Here we present the experimental realization of such a device, yielding an unequalled displacement sensitivity of 2 x 10(-15) m x Hz(-1/2) for a 116-MHz mechanical oscillator at a temperature of 30 mK-a sensitivity roughly a factor of 100 larger than the quantum limit for this oscillator.     

三极管与场效应管的对照分析

用对照的方法对三极管与场效应管及其放大电路进行了分析,尤其是将三极管也视为电压控制器件来与场效应管对比,以说明两种管子及其放大电路的工作原理、分析方法的实质是相同的。     

单电子晶体管/场效应管混合存储单元数值分析

基于背景电荷不敏感单电子晶体管／场效应晶体管混合存储单元利用单电子晶体管源漏电流随栅电压周期振荡的牲工作,以半经典的单电子正统理论为基础,采用计算机数值模拟的方法,分析了背景电荷不敏感单电子晶体管／常规场效应晶体管混合存储单元的工作原理和基本特性,提出了存储单元中分别以三结电容耦合单电子晶体管和电子旋转栅替代双结单电子晶体管的新结构,其主要思想是通过增加单电子器件中的串联随道结数来抑制各种噪声。模     

基于负微分电阻特性的SET/CMOS反相器

基于单电子晶体管(SET)和PMOS管串联产生的负微分电阻(NDR)特性,提出了一种新型的SET/CMOS反相器.该反相器利用NDR特性与NMOS负载管的电流-电压特性构成两个单稳态点,实现反相功能.应用HSPICE仿真器,采用精准的单电子晶体管的子电路模型及22nm CMOS预测技术模型对该反相器进行仿真,结果表明:该反相器的功能正确,具有比传统CMOS反相器更低的功耗;与其它单电子反相器相比,该反相器可在室温下实现输出电压全摆幅,且具有较低的传输延迟.     

贝尔实验室半导体器件的研制

叙述了贝尔实验室有关半导体器件的研制工作，主要论述了早期半导体器件的开发，点接触晶体管和结型晶体管，场效应晶体管（ＦＥＴ），发光二极管（ＬＥＤｓ），里德二极管（ＩＭＰＡＴＴ），以及光生伏打电池等     

基于周期特性的双岛单电子晶体管主方程模拟及改进

以双岛单电子晶体管（SET）为研究对象,采用稳态图和蒙特卡洛法分析双岛SET的周期特性,选取其中的7个典型状态,提出了双岛SET的简化主方程模拟方法,并利用分析所得SET的周期特性而改善简化主方程模拟方法的局限性.结果表明,所提出的模拟方法能够有效模拟双岛SET的电流和电压特性,并能扩展到多岛单电子晶体管.     

Di-electrophoresis assembly and fabrication of SWCNT field-effect transistor

In the process of fabricating nano electrical device or system based on single-walled carbon nanotube （SWCNT）, the controllable assembly and fabrication of SWCNT field-effect transistor （SWCNT FET） is a key issue. SWCNT FET is the most basic and important component in nano electronics. After microelectrode chip of back-gate FET is designed and fabricated, di-electrophoresis technology is adopted to realize the controllable alignment and assembly of SWCNTs, based on dispersing SWCNT by sodium dodecyl sulphate （SDS） facilitated ultra-sonication technique and removing impurities by centrifugal technique. The experiments of SWCNTs assembly demonstrate that SWCNTs are aligned and assembled uniformly at the microelectrodes gap with the alignment density nearly proportional to di-electrophoresis duration and solution concentration. After the processes of rinsing, drying and improving, metallic SWCNTs among the assembled SWCNTs are burned out and residual SDS is removed, and perfect field-effect performance of SWCNT FET is eventually obtained.     

一种SET的SPICE宏模型及SET/CMOS混合系统仿真研究

基于单电子晶体管(SET)数学分析模型,改进了它的SPICE宏模型.该模型考虑了背景电荷的影响,由1个电压控制电流源、1个电压控制电压源构成.与准分析模型相比较,该模型准确地表现了SET的I-U特性.通过A/D转换器的仿真实例表明,所设计的3位SET/CMOS混合系统具有良好的适用性和精确度,可以推广到SET/CMOS混合系统的管子级设计.     

A single-atom quantum memory

The faithful storage of a quantum bit (qubit) of light is essential for long-distance quantum communication, quantum networking and distributed quantum computing. The required optical quantum memory must be able to receive and recreate the photonic qubit; additionally, it must store an unknown quantum state of light better than any classical device. So far, these two requirements have been met only by ensembles of material particles that store the information in collective excitations. Recent developments, however, have paved the way for an approach in which the information exchange occurs between single quanta of light and matter. This single-particle approach allows the material qubit to be addressed, which has fundamental advantages for realistic implementations. First, it enables a heralding mechanism that signals the successful storage of a photon by means of state detection; this can be used to combat inevitable losses and finite efficiencies. Second, it allows for individual qubit manipulations, opening up avenues for in situ processing of the stored quantum information. Here we demonstrate the most fundamental implementation of such a quantum memory, by mapping arbitrary polarization states of light into and out of a single atom trapped inside an optical cavity. The memory performance is tested with weak coherent pulses and analysed using full quantum process tomography. The average fidelity is measured to be 93%, and low decoherence rates result in qubit coherence times exceeding 180 microseconds. This makes our system a versatile quantum node with excellent prospects for applications in optical quantum gates and quantum repeaters.     

基于SET/MOS混合结构的表决器电路的设计

基于单电子晶体管(SET)的库仑阻塞和库仑振荡效应,利用SET和MOS管的互补特性,提出了一种基于SET/MOS混合电路的新型表决器电路.利用HSPICE对所设计的表决器电路进行仿真验证,仿真结果表明SET/MOS混合电路能够实现表决器的功能.与传统CMOS电路相比,该SET/MOS混合电路使用的管子数目大大减少,功耗...     

基于SET/MOS混合结构的奇偶校验码产生电路的设计

基于单电子晶体管(SET)的库仑振荡效应和多栅输入特性,利用SET和金属氧化物半导体场效应晶体管(MOS管)的互补特性,设计了基于SET/MOS混合电路的奇偶校验码产生电路.利用HSPICE对所设计电路进行仿真验证,结果表明,该电路能够实现产生奇偶校验码的功能.该SET/MOS混合电路的实现只需要1个PMOS管、1个N...     

纳米双栅MOSFETs的量子格林函数模拟

采用一种量子动力学模型研究纳米MOSFET(场效应管)电流特性.该模型基于二维NEGF(非平衡格林函数)方程和Poisson方程自洽全量子数值解.使用该方法研究了纳米双栅MOSFET结构尺寸对电流特性的影响.模拟结果显示:越细长的沟道,器件的短沟效应越弱,器件的亚阈值斜率随栅氧化层增厚而加大.另外,通过分析器件不同区域的散射自能效应,得出减缓纳米双栅MOSFET电流性能下降的途径.所用模型具有概念清晰,求解稳定等特点.作为多体量子模型,本方法可应用于一维量子线及量子点阵列所构成的纳米器件,并有望在纳米MOSFET器件设计中得以应用.     

Exchange-biased quantum tunnelling in a supramolecular dimer of single-molecule magnets

Various present and future specialized applications of magnets require monodisperse, small magnetic particles, and the discovery of molecules that can function as nanoscale magnets was an important development in this regard. These molecules act as single-domain magnetic particles that, below their blocking temperature, exhibit magnetization hysteresis, a classical property of macroscopic magnets. Such 'single-molecule magnets' (SMMs) straddle the interface between classical and quantum mechanical behaviour because they also display quantum tunnelling of magnetization and quantum phase interference. Quantum tunnelling of magnetization can be advantageous for some potential applications of SMMs, for example, in providing the quantum superposition of states required for quantum computing. However, it is a disadvantage in other applications, such as information storage, where it would lead to information loss. Thus it is important to both understand and control the quantum properties of SMMs. Here we report a supramolecular SMM dimer in which antiferromagnetic coupling between the two components results in quantum behaviour different from that of the individual SMMs. Our experimental observations and theoretical analysis suggest a means of tuning the quantum tunnelling of magnetization in SMMs. This system may also prove useful for studying quantum tunnelling of relevance to mesoscopic antiferromagnets.     

一种基于互补型单电子晶体管D触发器设计

基于单电子晶体管(SET)的I-U特性和CMOS数字电路设计思想,提出了一类互补型SET逻辑门.在对由SET反相器构成的双稳态电路进行分析的基础上,提出了3种R-S触发器,最终得出了D触发器.通过选取1组SET参数,使触发器输入和输出高低电平接近于0.02 V和0,解决了电平匹配问题.SET的SPICE宏模型验证了设计的正确性.     

Pulsed metal organic chemical vapor deposition of InAlN-based heterostructures and its application in electronic devices

As a promising group III-nitride semiconductor material, InAlN ternary alloy has been attracted increasing interest and widespread research efforts for optoelectronic and electronic applications in the last 5 years. Following a literature survey of current status and progress of InAlN- related studies, this paper provides a brief review of some recent developments in InAlN-related III-nitride research in Xidian University, which focuses on innovation of the material growth approach and device structure for electronic applications. A novel pulsed metal organic chemical vapor deposition （PMOCVD） was first adopted to epitaxy of InAlN-related heterostructures, and excellent crystalline and electrical properties were obtained. Furthermore, the first domestic InAlN-based high-electron mobility transistor （HEMT） was fabricated. Relying on the PMOCVD in combination with special GaN channel growth approach, high-quality InAlN/GaN double-channel HEMTs were successfully achieved for the first time. Additionally, other potentiality regarding to AlGaN channel was demonstrated through the successful realization of nearly lattice-matched InAlN/AlGaN heterostructures suitable for high-voltage switching applications. Finally, some advanced device structures and technologies including excellent work from several research groups around the world are summarized based on recent publications, showing the promising prospect of InAlN alloy to push group III-nitride electronic device performance even further.     

Coherent properties of a two-level system based on a quantum-dot photodiode

Present-day information technology is based mainly on incoherent processes in conventional semiconductor devices. To realize concepts for future quantum information technologies, which are based on coherent phenomena, a new type of 'hardware' is required. Semiconductor quantum dots are promising candidates for the basic device units for quantum information processing. One approach is to exploit optical excitations (excitons) in quantum dots. It has already been demonstrated that coherent manipulation between two excitonic energy levels--via so-called Rabi oscillations--can be achieved in single quantum dots by applying electromagnetic fields. Here we make use of this effect by placing an InGaAs quantum dot in a photodiode, which essentially connects it to an electric circuit. We demonstrate that coherent optical excitations in the quantum-dot two-level system can be converted into deterministic photocurrents. For optical excitation with so-called pi-pulses, which completely invert the two-level system, the current is given by I = fe, where f is the repetition frequency of the experiment and e is the elementary charge. We find that this device can function as an optically triggered single-electron turnstile.     

基于Windows 2000的PCI接口设备驱动程序开发

以在W indows 2000环境中编制PMC-Sirra 7364卡驱动程序为例,介绍了在W in-dows 2000系统下开发PCI接口设备驱动程序的基本步骤、程序构架和常用函数,以及实现七号信令网链路接口到PC主机之间的PCI接口连接。该技术也可推广用于开发CompactPCI接口设备的驱动程序,从而为开发PC机在工业控制中的应用提供了一种便捷方法。     

Single artificial-atom lasing

Solid-state superconducting circuits are versatile systems in which quantum states can be engineered and controlled. Recent progress in this area has opened up exciting possibilities for exploring fundamental physics as well as applications in quantum information technology; in a series of experiments it was shown that such circuits can be exploited to generate quantum optical phenomena, by designing superconducting elements as artificial atoms that are coupled coherently to the photon field of a resonator. Here we demonstrate a lasing effect with a single artificial atom--a Josephson-junction charge qubit--embedded in a superconducting resonator. We make use of one of the properties of solid-state artificial atoms, namely that they are strongly and controllably coupled to the resonator modes. The device is essentially different from existing lasers and masers; one and the same artificial atom excited by current injection produces many photons.     

A tunable carbon nanotube electromechanical oscillator

Nanoelectromechanical systems (NEMS) hold promise for a number of scientific and technological applications. In particular, NEMS oscillators have been proposed for use in ultrasensitive mass detection, radio-frequency signal processing, and as a model system for exploring quantum phenomena in macroscopic systems. Perhaps the ultimate material for these applications is a carbon nanotube. They are the stiffest material known, have low density, ultrasmall cross-sections and can be defect-free. Equally important, a nanotube can act as a transistor and thus may be able to sense its own motion. In spite of this great promise, a room-temperature, self-detecting nanotube oscillator has not been realized, although some progress has been made. Here we report the electrical actuation and detection of the guitar-string-like oscillation modes of doubly clamped nanotube oscillators. We show that the resonance frequency can be widely tuned and that the devices can be used to transduce very small forces.