Annalen der Physik最新文献

This study primarily focuses on exploring the nature of anisotropic spheres within the framework of extended symmetric teleparallel gravity. To accomplish this, an anisotropic matter distribution for $��f�(�Q�,�T�)�$ gravity model with Tolman–Kuchowicz spacetime is considered. Through this analysis, the necessary conditions for matching the interior and exterior geometries of the spheres are discussed and calculated the values of the unknown parameters involved. Furthermore, the physical properties of these spheres are analyzed using observational data from compact objects. The results demonstrate that the interior solutions obtained for anisotropic spheres fulfill all requisite physical criteria, thereby ensuring the stability of our model.

Photon-assisted quantum phase transitions (QPTs) are studied in a cavity optomechanical system that consists of one optical cavity and two nonlinear mechanical resonators and explore ground-state properties of quantum phases. It is indicated that the cavity mode can induce effective two-phonon tunneling interaction between two mechanical resonators. It is found that QPTs between the localization phase (LP) and delocalization phase (DP) of phonons can happen through tuning the phonon tunneling interaction. It is shown that the photon-assisted QPT is the second order QPT. Ground-state properties of the quantum phases are also investigated. It is indicated that the ground state of the LP is a separable squeezed state while the ground state of the DP is an entangled state. The results open a new way to engineer quantum phases and QPTs in macroscopic mechanical systems and can benefit a wide range of criticality-enhanced quantum sensing applications.

Lorentz invariance belongs to the fundamental symmetries of nature. It is basic for the successful Standard Model of Particle Physics. Nevertheless, within the last decades, Lorentz invariance has been repeatedly questioned. In fact, there exist different research programs addressing this problem. It is argued that a most adequate understanding of a possible violation of Lorentz invariance is achieved in the framework of the gauge-theoretic approach to gravity: a non-vanishing nonmetricity of a metric-affine geometry of spacetime heralds the violation of the Lorentz symmetry.

In this paper, an all-dielectric metamaterial structure based on 3D printed is studied. The structure is composed of a 2 × 2 array of hollow cylinders. The electromagnetically induced transparency-like (EIT-like) effect is obtained by analyzing its transmission, and the mechanism of EIT-like is analyzed by electromagnetic field distribution. The mechanism of EIT-like is Mie resonance in the structure. The results demonstrate that the all-dielectric metamaterial structure can obtain slow light effect, and the group index is >800. The research results have potential applications in slow light devices, sensing, and detection on microwave communication systems.

Magnons are viewed as local deviations from the ordered state. Usually, the spin magnetic moment of magnons is considered. In a 3D-confined structure of a magnetic insulator with magnetodipolar mode (MDM) oscillations, an orbital angular momentum (OAM) as well as a spin angular momentum (SAM) can be observed along a static magnetic field. In such a confined structure as quasi-2D ferrite disk, energy levels of MDM oscillations are quantized. Quantum confinement is characterized by a half-integer internal OAM, which is also associated with a circulating energy flow. The observation of MDM resonances in the 3D-confined structure of a magnetic insulator is due to the interaction of two subsystems: ferromagnetic and electric polarization orders. The coupling states of these two concurrent orders, caused by OAMs, are considered as magnetoelectric (ME) states. The near fields of MDM resonators are characterized by simultaneous violation of time reversal and inversion symmetry. This plays a significant role in the problems of strong light-matter interaction regime and quantum atmosphere. The analysis of SAM and OAM in 3D-confined magnetic insulators becomes very important for the realization of ME meta-atomic structures. Current interest lies in considering such artificial systems as subwavelength ME quantum emitters of electromagnetic radiation.

A scheme to construct microwave-to-optical conversion and amplification using a hybrid cavity optomagnonics system is presented. A yttrium iron garnet (YIG) sphere with nonlinearity couples to optical transverse-electric (TE) and transverse-magnetic (TM) whispering gallery modes and a microwave mode. It is shown that the TM classical mode can control the quantum signals input from the microwave mode transmission into the optical TE mode. Due to the nonlinearity of the YIG sphere as well as effective magnon-optical nondegenerate parametric amplification form interaction, the microwave quantum signals can be amplified and transmitted into the optical TE mode. The current system can function well as a quantum transistor, which is important for constructing a quantum circuit using a cavity optomagnonics system.

The formalism of generalized quantum histories allows a symmetrical treatment of space and time correlations, by taking different traces of the same history density matrix. In this framework, the characterization of spatial and temporal entanglement is revisited. An operative protocol is presented, to map a history state into the ket of a static composite system. It is demonstrated, by examples, how the Leggett–Garg and the temporal Clauser-Horne-Shimony-Holt (CHSH) inequalities can be violated in this approach.

Advanced kirigami/origami techniques have enabled the flexible transformation of planar patterns into exquisite three-dimensional (3D) structures and provided a new paradigm to control electromagnetic waves with remarkable reconfigurability and functionality. The practical applications of kirigami/origami metasurfaces are prospective due to their diversified wave-manipulation capabilities, which demonstrate advantages such as compactness, lightweightness, deployability, and scalability. In this article, a comprehensive overview of the most recent advancements in the field of kirigami/origami metasurfaces is provided. This includes the concept of kirigami/origami, the practical implementations of kirigami/origami meta-structures, and the application aspects of kirigami/origami metasurfaces in the control of electromagnetic waves. In the conclusion, future challenges and promising pathways of this field are also envisioned from the own perspectives.

Network Nonlocality is an advanced study of quantum nonlocality that comprises network structure beyond Bell's theorem. The development of quantum networks has the potential to bring a lot of technological applications in several quantum information processing tasks. Here, the focus is on how the role of the independence of the measurement choices by the end parties in a network works and can be used to affect the security in a quantum network. In both three-parties two-sources bilocal network and four-parties three-sources star network scenarios, this study is able to show, a practical way to understand the relaxation of the assumptions to enhance a real security protocol if someone wants to breach in a network communication. Theoretically, it have been proved that by relaxing the independence of the measurement choices of only one end party, a Standard Network Nonlocality (SNN) and more stronger Full Network Nonlocality (FNN) can be created and the maximum quantum violation by the classical no-signalling local model can be obtained. The distinguish between two types of network nonlocality, SNN and FNN, can also be made. It has been shown that FNN is a stronger correlation than SNN in the sense that the former comes in a scenario where all the sources must be nonlocal in nature.