宏观物体是否具有德布罗意波

在高中物理教材中经常直接认为宏观物体具有德布罗意波.本文从德布罗意波提出、实验验证结合最近的量子力学发展,得出宏观物体是否具有德布罗意波这个问题至今还没有答案,并不能确定.     

德布罗意与物质波理论

 路易斯一维克多·德布罗意(Louis-Victorde Broglie 1892-1987)是法国著名理论物理学家,物质波理论的创立者.德布罗意主要从事理论物理、尤其是关于量子问题的研究,他在该领域取得的重大研究成果为现代物理的发展做出了杰出的贡献.1924年11月,德布罗意在博士论文中阐述了著名的物质波理论,并指出电子的波动性.     

封面说明

今年是法国物理学家路易-德布罗意(1892—1987)提出实物粒子波粒二象性80周年．1923年年底，德布罗意吸取了法国物理学家布里渊关于环绕原子核运动的电子会在以太中激发出一种相位波和只有电子轨道适当时才能形成稳定的驻波的想法，去掉以太概念，直接把波动概念赋予电子本身，一个运动粒子相应一个正弦波，波长λ=h／p，P是粒子的动量，h是普朗克常量，这个式子后来称为德布     

波动力学的引路人——L.德布罗意

从社会和个人的角度探索了德布罗意成为波动力学之引路人的原因，并在此基础上进一步对德布罗意独具特色的治学方法作了尝试性的总结，章最后给出了几点现实性的总结，章最后给出了几点现实性的思考与启示。     

路易·德布罗意没有放弃

指出路易·德布罗意并没有放弃对正统量子力学的挑战 ;文章《波动力学的引路人———L 德布罗意》中所述与历史事实不符 .     

德布罗意标尺:利用物质波进行精密测量

<正>1923年,德布罗意提出一个全新的概念,这个革命性的概念表达形式非常简单:"可以将物质或能量的孤立部分与周期性现象相联系"。这个周期现象的德布罗意波长是λdB=h/mυ。德布罗意波向经典理论提出挑战。例如,在一个双缝中的电子衍射只可以假设为自由传播的非局域化的量子波。由于每个单一粒子可以用多     

德布罗意和物质波理论的诞生——纪念德布罗意诞辰110周年

1924年11月,巴黎大学举行了一场不同寻常的博士考试.尽管应试的年轻人发表了令人难以接受的新见解,但考试委员会成员们被应试者的聪明和勇气所感动,为他的大胆假设--物质波理论打开了绿灯.众所周知,物质波就是德布罗意波,这位应试者的名字将永远和物质波紧紧联系在一起.     

德布罗意关系式的相对论协变形式及物质波波速

从德布罗意关系及相对论的协变性出发,得到了四维协变形式的德布罗意关系式,并讨论了物质波的相速度、群速度及粒子运动速度之间的关系.     

德布罗意和狄拉克

 德布罗意同狄拉克之间的关系,甚至比他同薛定谔之间的关系还来得密切:德布罗意和他的二哥莫里斯·德布罗意由于研究X射线的吸收、散射及其光谱的缘由,很早就同英国曼彻斯特大学的卢瑟福及其在剑桥大学三一学院的乘龙快婿福勒有学术联系。德布罗意1923年10月13日发表于英国《自然》杂志第112卷2815期540页题名为“波和量子”的论文,就是由福勒推荐的.     

德布罗意和物质波的诞生

文章从历史的角度出发,记述德布罗意的学术成长道路,侧重考察和较详细地分析他创立物质波理论的光辉历程。     

Thermal quenching of photoluminescence in ZnO/ZnMgO multiple quantum wells following oxygen implantation and rapid thermal annealing

The temperature-dependent photoluminescence in oxygen-implanted and rapid thermally annealed ZnO/ZnMgO multiple quantum wells is investigated. A difference in the thermal quenching of the photoluminescence is found between the implanted and unimplanted quantum wells. Oxygen implantation and subsequent rapid thermal annealing results in the diffusion of magnesium atoms into quantum wells and thus, leads to an increased fluctuation in the potential of the quantum wells and the observation of a large thermal activation energy. However, a high dose of implantation results in large defect clusters and thus an additional nonradiative channel, which leads to a flat potential fluctuation and a small thermal activation energy.     

Enhancement of magnetoresistance sensitivity in Co/Cu/NiFe trilayers by softening the Co hard layer

Co/Cu/NiFe trilayers were prepared by sputtering without magnetic field applied. We have found that the Co(2 nm)Cu(1 nm)NiFe(2 nm) trilayer using Ta as buffer layer exhibits an enhanced magnetoresistance (MR) sensitivity by a factor of more than 6 and a low saturation field of 9.3 Oe. Experimental results have demonstrated that the low saturation field is attributed to the softening of the Co layer by depositing the Co(2 nm)Cu(1 nm)NiFe(2 nm) sandwich on Ta layer. The decrease of the coercivity of the Co layer also plays an important role in the enhancement of MR sensitivity by reducing the effective coercivity of the NiFe layer, which is discussed in terms of the change in interlayer coupling.     

Contactless electroreflectance of GaNyAs1−y/GaAs multi quantum wells: The conduction band offset and electron effective mass issues

Interband transitions in GaN_yAs_1−y/GaAs multi quantum well (MQW) samples with y=0.012 and 0.023 have been studied by contactless electroreflectance spectroscopy (CER). Optical transitions related to absorption in the GaAs barriers and in the GaN_yAs_1−y/GaAs QWs have been observed and analyzed. The GaAs related transition exhibits clear Franz-Keldysh oscillations with the period corresponding to the built-in electric field of 14 and 17 kV/cm for samples with y=0.012 and 0.023, respectively. The portion of the CER spectrum related to absorption in the GaN_yAs_1−y/GaAs QW exhibits two clear resonances which are attributed to optical transitions between the ground and excited states confined in the QWs. The resonance attributed to the ground state transition is associated with absorption between the first light- and heavy-hole subbands and the first electron subband (11L and 11H) while the resonance attributed to the excited state transition is associated with absorption between the second heavy-hole subband and the second electron subband (22H). The energies of the 11H and 22H transitions have been matched with those obtained from theoretical calculations performed within the effective mass approximation. Thus, the GaN_yAs_1−y/GaAs QWs are type-I structures with a conduction band offset, Q_C, between 70 and 80%. Moreover, the incorporation of N atoms into GaAs is found to cause a significant increase in the electron effective mass. The determined values of electron effective mass for GaN_yAs_1−y/GaAs QW with y=0.012 and 0.023 are 0.105m₀ and 0.115m₀, respectively.     

On the boundary-value problems and the validity of the Post constraint in modern electromagnetism

We recall that the theory of electromagnetism consists of three building blocks: (a) the inhomogeneous Maxwell equations for the electric and magnetic excitations (D,H) (which reflects charge conservation), (b) the homogeneous Maxwell equations for the electric and magnetic field strengths (E,B) (which reflects flux conservation), and (c) the constitutive relation between (D,H) and (E,B). In the recent paper [A. Lakhtakia, Boundary-value problems and the validity of the Post constraint in modern electromagnetism, Optik 117 (2006) 188-192], Lakhtakia proposed to change the standard boundary conditions in electrodynamics in order to exclude certain constitutive parameters. We show that this is inadmissible both from the macroscopic and the microscopic points of view.     

Photoreflectance spectroscopy of a Ga0.62In0.38N0.026As0.954Sb0.02/GaAs single quantum well tailored at 1.5 μm

Optical properties of a Ga_0.62In_0.38As_0.954N_0.026Sb_0.02/GaAs single quantum well (SQW) tailored at ∼1.5 μm have been investigated by photoreflectance (PR) spectroscopy. The identification of the optical transitions was carried out in accordance with theoretical calculations, which were performed within the framework of the usual envelope function approximation. Using this method, four confined states for both electrons and heavy holes have been found and the optical transitions between them have been determined. The obtained result corresponds to a conduction band offset ratio close to 80%. In addition, the effect of ex situ annealing has been investigated. Lineshape analysis of the PR transitions shows that one of the phenomena responsible for the blueshift of QW transitions is the change in the nitrogen nearest-neighbour environment from Ga-rich to In-rich environments.     

Electrodeposited Co–Cu/Cu multilayered microposts

X-ray lithography and electrodeposition were combined to deposit an array of Co–Cu/Cu multilayer microposts of 500 μm tall into deep recesses for novel giant magnetoresistance (GMR) architectures. A citrate-boric acid electrolyte was used with pulsed potential. The applied potential was determined through inspection of the polarization curve from linear sweep voltammetry, and scanning electron microscopy (SEM)/transmission electron microscope (TEM) confirmed the micropost layered structure. Room temperature magnetoresistance was reported for different bilayer sizes of the micropost, and up to 4% current perpendicular-to-plane giant magnetoresistance (CPP-GMR) with saturation values less than 1 T was observed.     

Lattice parameters and anisotropic thermal expansion of hexagonal boron nitride in the 10–297.5 K temperature range

Lattice parameters for hexagonal boron nitride (hBN) were determined using X-ray powder diffraction at a synchrotron-radiation source (beamline B2, Hasylab/DESY, Hamburg) in the previously uninvestigated temperature range from 10 K up to 297.5 K. The relative change of a and c with rise of temperature in the studied range is anisotropic and amounts to about -0.05% and +0.82%, respectively. The corresponding increase of the unit-cell volume is 0.73%. The evaluated values of thermal expansion coefficients derived from the lattice-parameter dependences on temperature are generally consistent with earlier data determined by interferometryfor T≥82 K. Received: 25 July 2001 / Accepted: 9 August 2001 / Published online: 17 October 2001     

Integration and characterization of aligned carbon nanotubes on metal/silicon substrates and effects of water

We report here a facile way to grow aligned multi-walled carbon nanotubes (MWCNTs) on various metal (e.g. gold, tungsten, vanadium and copper)/silicon electrically conductive substrates by aerosol-assisted chemical vapor deposition (AACVD). Without using any buffer layers, integration of high quality MWCNTs to the conductive substrates has been achieved by introducing appropriate amount of water vapor into the growth system. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) determination indicate tidy morphology and narrow diameter distribution of the nanotubes as well as promising growth rate suitable for industrial applications. Raman spectra analysis illustrates that the structural order and purity of the nanotubes are significantly improved in the presence of water vapor. The growth mechanism of the nanotubes has been discussed. It is believed that water vapor plays a key role in the catalyst-substrate interaction and nucleation of the carbon nanotubes on the conductive substrates. This synthesis approach is expected to be extended to other catalyst-conductive substrate systems and provide some new insight in the direct integration of carbon nanotubes onto conductive substrates, which promises great potential for applications in electrical interconnects, contacts for field emitters, and other electronic nanodevices.     

An experiment to distinguish between de Broglie-Bohm and standard quantum mechanics

An experiment is suggested that is capable of distinguishing between the de Broglie-Bohm theory and standard quantum mechanics.