自旋电子学和自旋注入

自旋电子学是一门新兴的学科，利用它制造的自旋电子器件，与传统的半导体器件相比，有着非易失性，提高数据处理速度，降低能量消耗和增加集成密度等优点，从而给现有的电子业带来革命性的变化，有效的自旋注入是自旋电子学面临的重大挑战之一，文中综述了欧姆式注入，隧道注入，弹道电子注入等几种重要的自旋注入方法以及它们的最新进展。     

自旋电子学研究进展

自旋电子学是上世纪 90年代以来飞速发展起来的新兴学科。与传统的半导体电子器件相比 ,自旋电子器件具有非挥发性、低功耗和高集成度等优点。电子学、光学和磁学的融合发展更有望产生出自旋场效应晶体管、自旋发光二极管、自旋共振隧道器件、THz频率光学开关、调制器、编码器、解码器及用于量子计算、量子通信等装置的新型器件 ,从而触发一场信息技术革命。文中介绍了自旋电子学的若干最新研究进展。     

半导体自旋电子学的研究与应用进展

自旋电子学是一门最新发展起来的涉及磁学、电子学以及信息学的交叉学科.自旋电子器件与普通半导体电子器件相比具有不挥发、低功耗和高集成度等优点.本文介绍了半导体自旋电子学的研究对象和内容,主要包括磁性半导体、自旋注入、自旋探测以及自旋输运等.本文综述了半导体自旋电子学目前的研究进展及其在自旋电子器件和量子信息处理中的应用.     

自旋电子学研究

本文对自旋电子学的起源,作为自旋源的稀磁半导体的制备和自旋电子学的应用及发展前景进行了综述。详细介绍了稀磁半导体的制备及自旋电子学在器件上的应用。     

硅基自旋注入研究进展

自旋注入、自旋探测和自旋操控是构建半导体自旋电子器件的基础.在硅基材料上采用电的方式进行自旋注入,有利于自旋器件与微电子芯片的集成化,是当前该领域的研究热点课题之一.简要概述了硅基自旋注入的研究进展,首先介绍了半导体自旋注入的原理和方法,着重评述了以磁隧道结(MTJ)结构为核心的硅基自旋注入的研究进程,然后详细论述了硅基自旋注入的测试原理、器件结构扣实验方法,最后给出了硅基自旋注入的主要研究目标和发展方向,并展望了硅基自旋电子器件的前景.     

自旋电子学及其器件

1988年Fert与Grunberg科研小组彼此独立地在铁/铬多层膜纳米结构中发现了高达50％的磁电阻效应,从此自旋电子学诞生了.目前,自旋电子学已经发展出磁读头、磁电隔高耦合器、磁随机存储器(MRAM)、微波探测器等器件,年产值近1000亿美元.同时,通过与其它学科的结合,半导体自旋电子学、有机自旋电子学等均成为物理研究的前沿.因此,大量中外院士与专家认为自旋电子学及器件很有可能成为世界第四次产业革命的导火索.     

自旋电子学研究的最新进展

自旋极化电子的高效注入、自旋霍尔效应和自旋流的产生与探测都是目前自旋电子学中热门研究专题,世界一些著名学术刊物屡见报道。对这些重要内容的理论和实验的最新研究成果进行了介绍。通过自旋极化电子高效注入方法和材料的研究,人们期望研制出新一代自旋电子器件,进而实现应用电子自旋传输、记录和存储信息的目标。近期实验给出,自旋极化电子从铁磁金属注入半导体和金属都获得较高的极化率。各种注入方法中,自旋流直接注入法目前备受关注,因为自旋霍尔效应为自旋流的产生与探测提供了新的途径,即自旋霍尔效应可以产生自旋流,但因无霍尔电压故不容易测量;而逆自旋霍尔效应又将自旋流转化为电流,使得难以测量的自旋流又可以直接用电学方法测量。     

自旋电子学及其器件应用

介绍了近年来自旋电子学研究概况及器件应用，并展望了半导体自旋新器件的研究和发展。     

自旋电子学器件研发动态

介绍了自旋电子学在电场调控载流子的自旋取向、拓扑绝缘体的材料制备和量子输运等方面的协同创新动态,以及自旋转矩二极管、自旋电子智能传感器等器件的研究进展,基于市场预测指出了自旋电子学器件的巨大发展空间。     

自旋电子学、自旋电子器件及GaAs中电子自旋弛豫研究

评述了自旋电子学及自旋电子器件的发展,自旋电子器件的应用,半导体自旋电子学的研究内容及目前的研究现状．给出了我们的有关GaAs中电子自旋偏振与相干弛豫的研究结果．     

半导体材料中自旋极化的光学注入与探测

综述了自旋电子学的一些新进展,重点介绍了自旋极化的光学注入、弛豫机制和光学探测等方面的内容,并涉及到与自旋有关的自旋霍尔效应(SHE)和纯自旋流等物理效应.     

Spin‐Torque Manipulation for Hydrogen Sensing

External manipulation of spin‐orbit torques (SOTs) promises not only energy‐efficient spin‐orbitronic devices but also versatile applications of spin‐based technologies in diverse fields. However, the external electric‐field control, widely used in semiconductor spintronics, is known to be ineffective in conventional metallic spin‐orbitronic devices due to the very short screening length. Here, an alternative approach to control the SOTs by using gases is shown. It is demonstrated that the spin‐torque generation efficiency of a Pd/Ni₈₁Fe₁₉ bilayer can be reversibly manipulated by the absorption and desorption of H₂ gas, which appears concomitantly with the change of the electrical resistance. It is found that compared with the change of the Pd resistance induced by the H₂ absorption, the change of the spin‐torque generation efficiency is almost an order of magnitude larger. This result provides a new method to externally manipulate the SOTs and paves a way for developing more sensitive hydrogen sensors based on the spin‐orbitronic technology.     

Fe/GaAs中自旋注入效率的研究

自旋电子学是近年来发展迅速的一个研究领域,利用了传导电子自旋这一自由度的自旋电子器件以其提高数据处理速度、降低能量消耗、容易增加集成密度等优点正引起人们的空前关注.文中阐述了自旋的漂移-扩散方程,并对以Fe/GaAs为代表的铁磁性金属/半导体结构(FM/SC)进行了简单分析.如果选取参数适当,可以在Fe/GaAs结中获得较大的自旋注入效率.     

Robustness of Spin Polarization in Graphene‐Based Spin Valves

The decrease of spin polarization in spintronics devices under the application of a bias voltage is one of a number of currently important problems that should be solved. Here, an unprecedented robustness of the spin polarization in multilayer‐graphene spin valves at room temperature is revealed. Surprisingly, the spin polarization of injected spins is constant up to a bias voltage of +2.7 V and ?0.6 V in positive‐ and negative‐bias voltage applications at room temperature, respectively, which is superior to all spintronics devices. This finding is induced by suppression of spin scattering due to an ideal‐interface formation. Furthermore, an important accordance between theory and experiment in molecular spintronics is found by observing the fact that the signal intensity in a local scheme is double that in a nonlocal scheme, as theory predicts, which provides construction of a steadfast physical basis in this field.     

Spin Filtering through Single‐Wall Carbon Nanotubes Functionalized with Single‐Stranded DNA

High spin polarization materials or spin filters are key components in spintronics, a niche subfield of electronics where carrier spins play a functional role. Carrier transmission through these materials is “spin selective,” that is, these materials are able to discriminate between “up” and “down” spins. Common spin filters include transition metal ferromagnets and their alloys, with typical spin selectivity (or, polarization) of ≈50% or less. Here carrier transport is considered in an archetypical one‐dimensional molecular hybrid in which a single wall carbon nanotube (SWCNT) is wrapped around by single stranded deoxyribonucleic acid (ssDNA). By magnetoresistance measurements it is shown that this system can act as a spin filter with maximum spin polarization approaching ≈74% at low temperatures, significantly larger than transition metals under comparable conditions. Inversion asymmetric helicoidal potential of the charged ssDNA backbone induces a Rashba spin‐orbit interaction in the SWCNT channel and polarizes carrier spins. The results are consistent with recent theoretical work that predicted spin dependent conductance in ssDNA‐SWCNT hybrid. Ability to generate highly spin polarized carriers using molecular functionalization can lead to magnet‐less and contact‐less spintronic devices in the future. This can eliminate the conductivity mismatch problem and open new directions for research in organic spintronics.     

Innovation of Materials,Devices, and Functionalized Interfaces in Organic Spintronics

Organic spintronics has been attracting the interest of the scientific community because of its potential to complement the electronics industry by combining the spin and charge degrees of freedom. Synthesized organic materials with light elements have been widely applied in organic spintronics due to their intrinsic weak spin-orbit coupling and hyperfine interaction. Meanwhile, the prototypic devices in inorganic spintronics have been creatively utilized to fabricate analogous organic devices. The interfaces between organic materials and ferromagnetic electrodes in spintronic devices are diverse and can lead to many novel phenomena that influence the device performance. In this review, the novel organic materials, innovative devices, and functionalized interfaces in organic spintronics are comprehensively introduced. First, the fundamental concepts and parameters of organic spin devices are clarified. Subsequently, the organic materials applied in organic spintronics are classified, which include small molecules, polymers, and organic–inorganic hybrid perovskites. Moreover, several types of spin-related devices in this field are introduced and discussed. Thereafter, the functionalized interfaces of the spin-related devices are categorized and elaborated upon. Finally, a brief summary and future prospects are presented, which highlight the developments necessary in organic spintronics in the near future.     

Encoding Information on the Excited State of a Molecular Spin Chain

The quantum states of nano-objects can drive electrical transport properties across lateral and local-probe junctions. This raises the prospect, in a solid-state device, of electrically encoding information at the quantum level using spin-flip excitations between electron spins. However, this electronic state has no defined magnetic orientation and is short-lived. Using a novel vertical nanojunction process, these limitations are overcome and this steady-state capability is experimentally demonstrated in solid-state spintronic devices. The excited quantum state of a spin chain formed by Co phthalocyanine molecules coupled to a ferromagnetic electrode constitutes a distinct magnetic unit endowed with a coercive field. This generates a specific steady-state magnetoresistance trace that is tied to the spin-flip conductance channel, and is opposite in sign to the ground state magnetoresistance term, as expected from spin excitation transition rules. The experimental 5.9 meV thermal energy barrier between the ground and excited spin states is confirmed by density functional theory, in line with macrospin phenomenological modeling of magnetotransport results. This low-voltage control over a spin chain's quantum state and spintronic contribution lay a path for transmitting spin wave-encoded information across molecular layers in devices. It should also stimulate quantum prospects for the antiferromagnetic spintronics and oxides electronics communities.