School of Electrical and Computer Engineering

student name: Ihor Rusnak Research Topic: Optimization Problems in Wired and Wireless Sensor Networks Abstract: Wireless sensor networks (WSNs) are widely used today for many purposes, such as weather forecasting, environmental monitoring, seismic monitoring, target and hazard detection, fire and flood detection, and military surveillance. Therefore, efficient network data collection is highly valued. Using a tree as a routing structure can be quite effective for data collection. Furthermore, data collection in WSNs is efficient when a fixed amount of data can be aggregated into a single packet. Specifically, data aggregation helps reduce the number of transmissions and conserve sensor battery power. The collected data is periodically generated by sensors and transmitted to a specific node, called a sink. Since the sink is often located far from the sensors, multi-hop transmissions are used. In many WSN applications, time-critical transmission of collected data is required, but collisions may occur between messages transmitted simultaneously. Therefore, message scheduling through the network is required to minimize the time it takes for a message to reach the sink and avoid collisions. Network functions virtualization (NFV) is also a very important trend. It allows organizations to reduce costs and optimize service deployment. With virtualization, network functions that were previously executed on specialized hardware are replaced with software called virtual network functions (VNFs), which can be run on standard hardware. This allows network functions to be applied to data flows passing through network nodes hosting VNFs. These network nodes are called VNF nodes. To fully realize the benefits of network functions virtualization, each flow must be fully processed on these VNF nodes. Typically, due to budget constraints, only a limited number of nodes can be selected to host VNFs. Furthermore, each node typically has limited capacity, which must be used to process the multiple flows passing through it. Given these constraints, it is necessary to select a subset of nodes to host VNFs and determine a capacity allocation that maximizes the volume of traffic passing through them. In my research, I considered several problems using a tree-based data routing structure and data aggregation: minimum-cost data collection tree aggregation (MCDCTA), the problem of minimizing the latency of collision-free data aggregation in WSNs, where a fixed amount of data can be aggregated into a single packet, given the presence of multiple sinks in the network (MLCAMDAS-MultiSink), and a problem in the field of network function virtualization—the joint VNF placement and in-band power allocation problem (VPCA-ILP). To solve each of these complex problems, I have developed approximation algorithms and provided a theoretical analysis, determining their approximation coefficient and complexity. For one of the problems, the obtained results have been validated by extensive simulation results.

name: Ido Avrahami Advisor name: Prof. Adrian Stern Degree: Electrical and Computer Engineering :Seminar Summary Event-based dynamic vision sensors, which generate sparse spike-based outputs, are ideal for low-power appli- cations. Spiking Neural Networks are designed to process this data efficiently on asynchronous neuromorphic hardware. As event-based vision advances, understanding the vulnerability of Spiking Neural Networks to physical adversarial attacks becomes crucial. This work introduces a novel light-based adversarial attack on neuromorphic vision. We exploit undetectable optical events, specifically designed light pulses, to disrupt the temporal dynamics of event-based sensors. Our method demonstrates how these physical attacks can be tailored to the event-based data’s discrete and sparse nature while achieving high success rates. name: Yoni Barta Degree: M.Sc. (Research Track), Electrical & Computer Engineering, BGU Advisors: Prof. Nir Shlezinger and Prof. Tirza Rotenberg Seminar title: Multiuser Localization with Leaky-Wave Antennas (LWAs) for THz Communications Abstract: Next-generation wireless networks are expected to exploit the terahertz (THz) band, but high path loss and hardware complexity make conventional antenna arrays costly. Leaky-Wave Antennas (LWAs) offer a low-cost alternative that couples frequency to radiation angle, enabling beam scanning with a single passive element. This talk presents a physics-aware signal model for multiuser localization using a single LWA receiver over a wide THz band, and introduces two estimation methods: a maximum-likelihood (ML) approach and a low-complexity spectral correlation/beamforming method tailored to the LWA’s frequency–angle response. We also adapt a MUSIC-style subspace estimator by treating frequency subbands as virtual array elements, and derive Cramér–Rao bounds for AoA estimation under the LWA model. Simulations show accurate single- and multiuser AoA recovery within the effective aperture, with the proposed low-complexity method closely tracking ML performance and, in some cases, rivaling conventional ULA-based baselines—while using a single, cost-efficient THz antenna.

Quantum Light in van der Waals Heterostructures: From Ultrastrong Coupling in the Terahertz Regime to Quantum Sensing with Atomic Resolution Dr. Igor Khanonkin Abstract Two-dimensional (2D) materials provide a versatile platform for engineering light–matter interactions across vastly different regimes, paving the way toward quantum systems with tailored properties. In this talk, I will present results that outline a unified framework in which 2D materials bridge condensed matter physics and quantum optics, opening new directions for cavity-controlled electronic phases, collective emission, and quantum sensing at the atomic scale. I will begin by describing the development of a sub-diffraction terahertz (THz) spectroscopy technique [1], which enabled the first demonstration of ultrastrong coupling between THz cavity modes and a tunable interband transition in bilayer graphene device. The observed cavity-induced resonance emerges from the interband continuum and mimics a Coulomb-bound exciton. These experiments reveal a coupling strength exceeding 40% of the mode frequency, marking the onset of a non-perturbative regime of hybrid exciton–photon states in quantum materials. Next, I will discuss how optically active defects in hexagonal boron nitride (hBN) provide a promising platform for quantum sensing with atomic-scale resolution [2]. Unlike NV centers in diamond, which lie about 10 nm below the surface and thus limit spatial resolution, B-centers in hBN can reside within only a few atomic layers of the target material. This enables their integration into van der Waals heterostructures and AFM-like tips to directly visualize Moiré patterns and strongly correlated electronic states with nanometer precision. Finally, I will present our observation of superradiance in ensembles of quantum emitters in hBN, where emitters separated by sub-wavelength distances collectively emit photons in short, intense bursts—exhibiting the hallmark signatures of cooperative spontaneous emission. [1] F. Helmrich, H.S. Adlong, I. Khanonkin, M. Kroner, G. Scalari, J. Faist, A. Imamoglu, T.F. Nova. “Cavity-Driven Attractive Interactions in Quantum Materials”. Preprint arXiv:2408.00189v3 (2024). [2] L. Liu*, I. Khanonkin*, J. Eberle*, B. Rizek, S. Falt, K. Watanabe, T. Taniguchi, A. Imamoglu and M. Kroner. “Quantum Emitters in Ultra-Thin Hexagonal Boron Nitride Layers”, Preprint arXiv:2507.02633v1 (2025). Short Bio Dr. Igor Khanonkin is a Rothschild Postdoctoral Fellow at ETH Zurich’s Institute of Quantum Electronics, where he drives two pioneering research directions in Prof. Atac Imamoglu’s group: THz cavity quantum electrodynamics and super-resolution quantum sensing using optical active defects in 2D materials. He completed his PhD at the Technion, Faculty of Electrical and Computer Engineering, under the supervision of Prof. Gadi Eisenstein, focusing on nonlinear and quantum photonics. Dr. Khanonkin also established Israel’s participation in the International Physicists’ Tournament (IPT).