Theory and Applications of Observability of Classical And Quantized Radiation Fields

[990024 . ziolkowski]在经典的电磁辐射理论中，存在一定的不辐射的局域电荷-电流分布。这样的源，通常被称为非辐射源，产生的场本身被限制在源[1]的局部区域内。对非辐射源的研究涉及标量源[2,3,4,5]和电磁源[1,6,7,8]以及确定性源和随机源[9,10,11]。问题是，在量子理论中，非辐射源是否有（或没有）对应的源。令人惊讶的是，这个基本问题以前似乎没有被解决过。提出的研究计划的主要目标是为经典和量子化场发展一种新的非辐射源理论，并解决发展理论的潜在和具体应用。具体的理论和应用目标的预测研究描述如下。我们建议处理（经典和量子电动力学）与单色和瞬态（例如，脉冲）源和场。提出的研究的经典部分将集中在开发新的工具来分析和合成非辐射源的时间和频率域。这部分项目的目标包括：1.)在时域发展新的逆源和非辐射源理论，2.)发展完整的向量函数集来表示单色和瞬态紧支撑的非辐射源，3.)探索非辐射源和其他波对象之间的基本（和潜在的实用）联系，如标量和矢量势以及电磁学逆源问题的最小能量解。按照这些思路提出的工作预计将与提议者先前针对标量源和字段所做的工作并行（并进行推广）。这项工作包括反源问题[12]的新公式，以及非辐射源[13]及其与最小能量源和完美辐射源[14]的联系的新描述。所概述的工作的理论组成部分也有望使人们了解量子理论中非辐射源的性质，从而有助于对源和散射体及其场的可观测性有更基本的理解。目的是要结论性地回答量子理论中非辐射源的存在问题。此外，发展的理论可能对量子理论的基本方面产生影响，特别是对一个有争议的、尚未完全理解的量子力学现象，即Aharonov-Bohm效应，其中带电粒子可以受到经典的局域源及其在场（因此对粒子的力）消失的区域中的场的影响[15,16]。因此，我们还建议研究Aharonov-Bohm效应与量子化辐射场的可观测性之间的联系。这一发展起来的理论可能会为新的通信方案（基于非辐射源）以及询问源和散射体（硬件和算法）的新技术奠定基础。后一个方面构成了第二部分的重点研究，旨在应用。感兴趣的应用依赖于通过量子力学实验（即新的场传感设备）感知源（例如信息）的某些特征的可能性，这些特征本来是不可观察的（即通过经典传感器（天线））。因此，基于Aharonov-Bohm效应和/或其他非常规的量子力学场-粒子相互作用效应的新场传感设备的系统级设计也是拟议努力的潜在结果。与通信技术特别相关的是产生局限（局部化）的场的可能性，经典地，在源的支持区域（天线结构）内，但这不是量子力学的。后一种可能性潜在地打开了一扇窗，为有效、安全地传输由传统源（天线）产生，但通过非常规的量子电动力场传感器感知的场观测（sighal）打开了一扇窗。通过这种方式，人们可以获得额外的灵活性（在天线对天线通信中不可用），通过一个“通道”传输全部或部分要传输的信息，该通道只对量子电场传感器开放，而传统的场传感器（接收天线）不可用。总之，技术影响的主要领域-将作为拟议努力的一部分加以探索-是1.)新的现场传感设备，2.)新的通信技术和3.)用于询问源和散射体的新算法和硬件

9900246ZiolkowskiIn the classical theory of electromagnetic radiation, there are certain localized charge-current distributions which do not radiate. Such sources, commonly referred to as nonradiating sources, generate fields which are themselves confined within the region of localization of the source [1]. Investigations on nonradiating sources have addressed both scalar [2, 3, 4, 5] and electromagnetic sources [1, 6, 7, 8] as well as both deterministic and random sources [9, 10, 11]. The question arises whether nonradiating sources have (or not) a counterpart in the quantum theory. Surprisingly, this fundamental question does not appear to have been addressed before. The main goal of the proposed program of research is to develop a new theory of nonradiating sources for both classical and quantized fields and to address potential and concrete applications of the developed theory. Specific theoretical and applicational aims of the projected research are described below.We propose to deal (classically and quantum-electrodynamically) with both monochromatic and transient (e.g., pulsed) sources and fields. The classical component of the proposed research will focus on developing new tools for analysis and synthesis of nonradiating sources in the time and frequency domains. The objectives of this portion of the project include: 1.) developing a new inverse source and nonradiating source theory in the time domain, 2.) developing complete sets of vector functions to represent monochromatic as well as transient nonradiating sources of compact support, and 3.) exploring fundamental (and potentially practical) connections between nonradiating sources and other wave objects, such as the scalar and vector potentials and minimum energy solutions to the inverse source problem of electromagnetics. The proposed work along those lines is expected to parallel (and generalize) previous work by the proposers for scalar sources and fields. That work includes new formulations of the inverse source problem [12] as well as new descriptions of nonradiating sources [13] and of their connection with minimum energy sources and perfect radiators [14]. The theoretical component of the outlined effort is expected to give light, also, into the nature of nonradiating sources in the quantum theory, thereby contributing to a more fundamental understanding of the observability of sources and scatterers and their fields. The purpose is to answer conclusively the question of existence of nonradiating sources in the quantum theory. Furthermore, the developed theory could have impact in fundamental aspects of quantum theory and, in particular, in a controversial, not fully-understood, quantum-mechanical phenomenon, namely, the Aharonov-Bohm effect, wherein charged particles can be influenced by classical, localized sources and their fields in regions where the fields (and therefore the forces on the particles) vanish [15, 16]. Thus, we propose also to examine the connection between the Aharonov-Bohm effect and the observability of quantised radiation fields.The developed theory could, potentially, set the stage for novel communication schemes (based on nonra-diating sources), as well as new techniques for interrogation of sources and scatterers (in both hardware and algorithms). The latter aspects constitute the focus of the second part of the proposed research, aimed at ap-plications. The applications of interest rely on the possibility of sensing via quantum-mechanical experiments (i.e., new field-sensing devices) certain features of a source (e.g., information) which would be otherwise (i.e., via classical sensors (antennas)) inherently unobservable. Thus, system-level designs for new field-sensing devices based, e.g., on the Aharonov-Bohm effect and/or other unconventional, quantum-mechanical field-particle interaction effects, are also potential outcomes of the proposed effort. Of particular relevance to communication technologies is the possibility of generating fields that are confined (localized), classically, within the source's region of support (antenna's structure), but that are not such quantum-mechanically. The latter possibility opens, potentially, a window for efficient, secured transmission of field-observables (sig-halS), generated by conventional sources (antennas) but sensed via unconventional, quantum-electrodynamic field-sensors. In this way, one would obtain, e.g., added flexibility (not available in antenna-to-antenna communication) for transmitting either all or part of the to-be-transmitted information via a "channel" that opens only to quantum-electrodynamic field-sensors while being unavailable to traditional field-sensors (receiving antennas). In summary, the main areas of technological impact - to be explored as part of the proposed effort - are 1.) novel field-sensing devices, 2.) new communications technology and 3.) new algorithms and hardware for interrogation of sources and scatterers.***