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We demonstrate nonreciprocal control of the speed of light by sending a microwave pulse through a cavity magnonics device. In contrast to reciprocal group velocity controlled by conventional electromagnetically induced transparency (EIT) effects, incorporating a dissipative magnon-photon coupling establishes a nonreciprocal EIT effect, allowing slow and fast light propagation in opposite directions at the same frequency with comparable amplitude. Remarkably, reversing the magnetic field enables a directional switch between nonreciprocal fast and slow light. This discovery may offer new possibilities for pulse time regulation in microwave signal communications, neuromorphic computing, and quantum signal processing.
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http://dx.doi.org/10.1103/PhysRevLett.134.196904 | DOI Listing |
Adv Mater
September 2025
Life-Like Materials and Systems, Department of Chemistry, University of Mainz, Duesbergweg 10-14, 55128, Mainz, Germany.
Movement is essential for living systems, enabling access to food, habitats, or escape from threats. Across scales, a key unifying principle is symmetry breaking to achieve non-reciprocal motion and accumulate work. In soft robotics, many actuators mimic biological responsiveness, but they typically exhibit reciprocal motion, where forward work is canceled in the return stroke - preventing work accumulation in cyclic operation.
View Article and Find Full Text PDFAdv Sci (Weinh)
August 2025
Faculty of Science and Engineering, Dalton Building, Manchester Metropolitan University, Manchester, M1 5GD, UK.
Active mechanical metamaterials have the potential to revolutionize material capabilities, by switching between different properties. The active mechanical metamaterial presented here can be remotely programmed to switch between compressive and shear deformation modes that cause stark changes in stiffness. The considered metamaterial uses controlled instabilities to change the buckling mode of electro-thermally activated beams.
View Article and Find Full Text PDFSci Rep
August 2025
National Creative Research Initiative Center for Spin Dynamics and Spin-Wave Devices, Nanospinics Laboratory, Department of Materials Science and Engineering, Seoul National University, Seoul, 08826, Republic of Korea.
Precise control of coupling strength, damping rate and nonreciprocity in photon-magnon systems is essential for advancing hybrid quantum technologies, including reconfigurable microwave components and quantum transducers. Here, we demonstrate magnetic field angle-dependent control of photon-magnon coupling and magnon dissipation in a cross-shaped microwave cavity supporting a spatially nonuniform radio-frequency (rf) magnetic field. By rotating the external magnetic field angle θ relative to the normal of the transmission line within the cavity plane, we simultaneously control the coherent coupling strength [Formula: see text], the ferromagnetic resonance (FMR) damping rate, and the system's nonreciprocal response.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
August 2025
Institute of Science and Technology Austria, Klosterneuburg 3400, Austria.
Cell and tissue movement in development, cancer invasion, and immune response relies on chemical or mechanical guidance cues. In many systems, this behavior is locally directed by self-generated signaling gradients rather than long-range, prepatterned cues. However, how heterogeneous mixtures of cells interact nonreciprocally and navigate through self-generated gradients remains largely unexplored.
View Article and Find Full Text PDFAdv Sci (Weinh)
August 2025
National Key Laboratory of Equipment State Sensing and Smart Support, College of Intelligence Science and Technology, National University of Defense Technology, Changsha, 410073, China.
Static nonreciprocity offers distinct outputs when switching the positions of action and reaction, which is of great interest for designing mechanical logic elements or soft robots. Existing mechanical metamaterials can present specific static nonreciprocal responses, but it remains challenging to obtain multiple and reprogrammable static nonreciprocal modes in a single microstructural topology. Here, a design method of cellular metamaterials is demonstrated via leaving cuts inside metacells, whose contact nonlinearity in the single metacell can offer orthogonal, uniaxial, shear (displacement and Poynting effect) static nonreciprocal modes.
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