Experimental evidence demonstrating that anomalous localization of waves can be induced in a controllable manner is reported. A microwave waveguide with dielectric slabs randomly placed is used to confirm the presence of anomalous localization. If the random spacing between slabs follows a distribution with a power-law tail (Lévy-type distribution), unconventional properties in the microwave-transmission fluctuations take place revealing the presence of anomalous localization. We study both theoretically and experimentally the complete distribution of the transmission through random waveguides characterized by α=1/2 ("Lévy waveguides") and α=3/4, α being the exponent of the power-law tail of the Lévy-type distribution. As we show, the transmission distributions are determined by only two parameters, both of them experimentally accessible. Effects of anomalous localization on the transmission are compared with those from the standard Anderson localization.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1103/PhysRevLett.113.233901 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Macromolecular interactions and geometrical confinement determine the 3D diffusion of ribosome-sized particles in live cells.
Proc Natl Acad Sci U S A
January 2025
Department of Chemical Engineering, Stanford University, Stanford, CA 94305.
The crowded bacterial cytoplasm is composed of biomolecules that span several orders of magnitude in size and electrical charge. This complexity has been proposed as the source of the rich spatial organization and apparent anomalous diffusion of intracellular components, although this has not been tested directly. Here, we use biplane microscopy to track the 3D motion of self-assembled bacterial genetically encoded multimeric nanoparticles (bGEMs) with tunable size (20 to 50 nm) and charge (-3,240 to +2,700 e) in live cells.
View Article and Find Full Text PDFIncreasing Neural-Based Pedestrian Detectors' Robustness to Adversarial Patch Attacks Using Anomaly Localization.
J Imaging
January 2025
Science and Research Department, Moscow Technical University of Communications and Informatics, 111024 Moscow, Russia.
Object detection in images is a fundamental component of many safety-critical systems, such as autonomous driving, video surveillance systems, and robotics. Adversarial patch attacks, being easily implemented in the real world, provide effective counteraction to object detection by state-of-the-art neural-based detectors. It poses a serious danger in various fields of activity.
View Article and Find Full Text PDFAnomalous Behavior of the Non-Hermitian Topological System with an Asymmetric Coupling Impurity.
Entropy (Basel)
January 2025
School of Integrated Circuits, Tsinghua University, Beijing 100084, China.
A notable feature of systems with non-Hermitian skin effects is the sensitivity to boundary conditions. In this work, we introduce one type of boundary condition provided by a coupling impurity. We consider a system where a two-level system as an impurity couples to a nonreciprocal Su-Schrieffer-Heeger chain under periodic boundary conditions at two points with asymmetric couplings.
View Article and Find Full Text PDFPractical Implementation of Federated Learning for Detecting Backdoor Attacks in a Next-word Prediction Model.
Sci Rep
January 2025
Research and Development Office, The Education University of Hong Kong, Hong Kong, China.
This article details the development of a next-word prediction model utilizing federated learning and introduces a mechanism for detecting backdoor attacks. Federated learning enables multiple devices to collaboratively train a shared model while retaining data locally. However, this decentralized approach is susceptible to manipulation by malicious actors who control a subset of participating devices, thereby biasing the model's outputs on specific topics, such as a presidential election.
View Article and Find Full Text PDFGlobal urban activity changes from COVID-19 physical distancing restrictions.
Sci Data
January 2025
Universities Space Research Association, Washington, DC, USA.
During the COVID-19 pandemic changes in human activity became widespread through official policies and organically in response to the virus's transmission, which in turn, impacted the environment and the economy. The pandemic has been described as a natural experiment that tested how social and economic disruptions impacted different components of the global Earth System. To move this beyond hypotheses, locally-resolved, globally-available measures of how, where, and when human activity changed are critically needed.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!