In this paper, we use weak measurement to study the mixed magneto-optical Kerr effects (MOKEs) in a magnetic single layer of Co and in organic/Co bilayer films. The relationship between the amplified shift and the MOKE parameters is theoretically established and then experimentally observed as a function of both the magnetization intensity and the magnetization direction in magnetic thin films with an arbitrary magnetization. Furthermore, we experimentally observe a magnetic coupling at the organic/ferromagnetic interface. Due to this being a robust coupling, there is a significant dependence of the amplified shift with the thickness of the organic layer. This work has value for its application in the magnetic measurement technique for the more general case based on weak measurement.

The present paper introduces a quantum weak measurement (WM) scheme for the measurement of the complex magneto-optical Kerr effect (MOKE). We achieve the simultaneous measurement of the Kerr rotation angle and the ellipticity in a single WM process by utilizing two auxiliary pointers derived from the same meter state. The experimental measurement precision for both the Kerr rotation angle and the ellipticity is capable of reaching 10−4 deg. This technique is also employed for the determination of the complex magneto-optical constant Q. The proposed method overcomes the limitation of acquiring the complex magneto-optical Kerr parameters through a multi-step measurement process, which was previously encountered. This breakthrough holds immense significance for efficiently measuring and applying the complex MOKE with high precision and cost-effectiveness.

Memristors have unique non-volatile characteristics that potentially can emulate biological synapses for applications in neural computing systems. However, the random formation of conductive filaments in these devices can cause various unreliability problems. In this work, films of a composite of ZnO nanoparticles and carbon nanotubes were prepared as functional layers for memristors by an in-situ growing strategy (ZnO@CNT-IS) using a straightforward high-temperature annealing treatment. This approach allowed for the formation of a high-quality films with uniform loading of ZnO nanoparticles on the carbon nanotubes, which contributed to a lower formation energy for oxygen vacancies and increased electron transfer rate. As a result, the memristors exhibited faster switching response speed, lower power consumption, and a stabilised switching ratio even after 2000 switching cycles. Based on the analog switching behaviour, the ZnO@CNT-IS-based devices showed significant biological synapse functions and plasticity, indicating their potential for high-density storage and neuromorphic computing.

The development of artificial intelligence has resulted in significant challenges to conventional von Neumann architectures, including the separation of storage and computation, and power consumption bottlenecks. The new generation of brain-like devices is accelerating its evolution in the direction of high-density integration and integrated sensing, storage, and computing. The structural and information transmission similarity between memristors and biological synapses signifies their unique potential in sensing and memory. Therefore, memristors have become potential candidates for neural devices. In this paper, we have designed an optoelectronic memristor based on a ZnO/Cu₂O structure to achieve synaptic behavior through the modulation of electrical signals, demonstrating the recognition of a dataset by a neural network. Furthermore, the optical synaptic functions, such as short-term/long-term potentiation and learn-forget-relearn behavior, and advanced synaptic behavior of optoelectronic modulation, are successfully simulated. The mechanism of light-induced conductance enhancement is explained by the barrier change at the interface. This work explores a new pathway for constructing next-generation optoelectronic synaptic devices, which lays the foundation for future brain-like visual chips and intelligent perceptual devices.

The purpose of this article is to take away some of the mystery associated with understanding the phenomenon of negative thermal expansion (NTE) in isotropic crystals. For sure, NTE is counter to our textbook intuition about the normal positive thermal expansion of chemical bonds, but there are now sufficient results from experimental and theoretical investigations to enable us to rationalise the existence of NTE in most materials with cubic symmetry, and indeed to be able to predict its possible existence in any new material. In this article, we posit the existence of four principles that can enable us to rationalise the existence of NTE: the existence of a network structure, the ability of the structure to support low-frequency vibrations, the spreading of the important vibrations into a sufficiently-large volume of reciprocal space, and the limiting factor of dynamic disorder. We describe these with regard to a number of key examples. We point out that the same principles will operate for anisotropic crystals, but we offer the caution that NTE in anisotropic materials can also arise from factors missing in isotropic materials. We also point out that NTE arises in the face of competing mechanisms that ordinarily would give positive thermal expansion, so the practical existence of NTE arises as a balance between mechanisms pulling in opposite directions. We therefore argue that one should not point to a single simplemechanismforNTE.Instead,NTEisassociatedwiththefourprinciplestogetherwithchemical effects that can tilt how these principles are balanced against the drive of the chemical bonds towards positive thermal expansion. There is a long-standing and well-demonstrated importance of glass ceramics for many technical and domestic applications, which practically achieve many of the goals of the NTE materials community. In the light of this, it is our feeling that the key achievement of much of NTE research over the past 30 years has not so much been in terms of finding alternative NTE materials as in what we have been able to learn from these materials, which in turn has enabled us to elucidate the general principles that underpin our understanding of how NTE materials work.