Special Section Papers

Tutorial on Electromagnetic Nonreciprocity and its Origins

By V. S. Asadchy, M. S. Mirmoosa, A. Díaz-Rubio, S. Fan, and S. A. Tretyakov

This article reviews the long history of research on electromagnetic nonreciprocity, its origins, and its implications. It aims to put into context the recent advances and progress in this area of research, and straighten up erroneous claims on what nonreciprocity actually implies.

Microwave Nonreciprocity

By A. Kord, D. L. Sounas, and A. Alù

This article reviews the various available approaches to nonreciprocity available for microwave technologies, from magnetic bias to temporal modulations and nonlinearities, discussing the advantages and draw- backs of each approach in terms of various metrics of performance, and providing a promising outlook for magnet-free nonreciprocal technology at microwave frequencies.

Integrated Nonreciprocal Photonic Devices With Dynamic Modulation

By I. A. D. Williamson, M. Minkov, A. Dutt, J. Wang, A. Y. Song, and S. Fan

This article reviews the use of time modulation to break reciprocity in photonic devices, their various implementations, and potential opportunities for photonic technology.

Regular Papers

Digital Twin in the IoT Context: A Survey on Technical Features, Scenarios, and Architectural Models

By R. Minerva, G. M. Lee, and N. Crespi

This survey covers state-of-the-art approaches and discusses major technologies that have contributed to the field of Digital Twin.

Software Vulnerability Detection Using Deep Neural Networks: A Survey

By G. Lin, S. Wen, Q.-L. Han, J. Zhang, and Y. Xiang

The survey provides a state-of-the-art treatment of deep-learning-/neural-network-based approaches for detecting software vulnera- bilities and identifies challenges in this field.

Scanning Our Past