Annalen der Physik最新文献

Non-Standard Coupling

The back-cover image illustrates the proposed quantum coupling between particles in heterostructures. Unlike standard coupling (the lattice with white squares), where the coupled particles interact only through their potential interaction V(x,y), when dealing with heterostructures (the lattice with colored squares) an additional type of coupling can arise, T(x,y), which shapes the structure of the quantum system by shaping the uncertainty relations followed by the specific type of coupling between the particles. For further details see article 2300363 by Tomer Shushi.

Jumping Platonic Solids

Macroscopic objects excited mechanically by vibrating plates represent simple systems that can exhibit complex dynamics, including quasi-chaotic behavior. Bouncing spheres were investigated for decades. Such mechanical excitation provides a basis for experimental studies of granular gases. The study of bouncing Platonic solids (see article number 2300349 by Ralf Stannarius and co-workers) adds more complexity such as coupling of rotational and translational degrees of freedom. Integrated intelligent sensor chips were employed to analyze the particle trajectories and rotations.

The influence of a a rectangular potential barrier on the quantum transport of fermions in silicene is explored. Specifically, analytical solutions are presented to derive transmission and reflection probabilities together with conductance. It is shown that the transmission is highly sensitive to both the barrier height and incident energy. As a result, the occurrence of Klein and resonant tunnelings is observed, with a significant dependence on the barrier width. Notably, it is found that perfect transmission extends beyond normal incidence, occurring at various oblique angles. Moreover, the transmission pattern exhibits a more fragmented structure with increasing barrier width, reminiscent of Fabry-Pérot resonances. In contrast, the conductance displays a non-monotonic dependence on incident energy and features rapid oscillations with a rising barrier height. However, at a constant barrier height, there is a minimal disparity among conductance profiles for high incident energy values. When incident energy equals the barrier height, the conductance experiences a local minimum. For a thin barrier, a substantial reduction in conductance is observed, unlike the oscillatory behavior seen with a thicker barrier. These findings underscore the progress in silicene research and offer a fresh perspective on the relativistic applications of tunneling in this material.

In this paper, symmetric Pearcey Gaussian beams (SPGBs) are studied in a Kerr medium. By varying the initial input power, the autofocusing ability of the beams is investigated, to find a clear restrictive relationship between the breath-like structure and the initial input power. The critical collapse power is investigated when SPGBs change from discrete beams to regular breath-like structure. Finally, the transmission of SPGBs is discussed under different phase modulation when SPGBs are affected by astigmatic, the whole beam is rotated and the angle of rotation can be controlled.

A relativistic diffusion model with cylindrical symmetry, which propagates an initial state based on quantum chromodynamics in time toward a thermal equilibrium limit, is derived from nonequilibrium–statistical considerations: adapting an existing framework for Markovian stochastic processes representing relativistic phase-space trajectories, a Fokker–Planck equation is obtained for the time evolution of particle-number distribution functions with respect to transverse and longitudinal rapidity. The resulting partially-evolved distribution functions are transformed to transverse-momentum and pseudorapidity space, and compared with charged-hadron data from the CERN Large Hadron Collider.

The common methods used for correcting chromatic aberration are typically based on multi-lens and multi-material systems, resulting in lens thicknesses that are several orders of magnitude greater than the wavelength and complex combination designs. A method to achieve the singlet achromatic microlens of the wavelength-scale thickness by utilizing high refractive index materials with an aspherical profile is proposed. A theoretical model based on the dispersion effect is developed to guide the selection of materials and the design of thicknesses for achieving chromatic aberration correction in singlet microlenses of a given diameter and numerical aperture. H-ZLaF68N (68N) glass, sapphire, and fused silica with relatively high to low refractive index are selected to prepare the singlet achromatic microlenses to verify the validity of the model. The thicknesses of three microlenses are 573, 737 nm, and 1.27 µm, respectively, and all of them have achieved achromatic correction as designed. This indicates that the high refractive index material not only achieves achromatic aberration but also reduces the thickness by ≈50% compared with the conventional low refractive index material of silica glass. The presented wavelength-scale singlet achromatic microlens hold significant promise for compact wearable devices, dynamic holography, and color projection displays.

It is shown that from the point of view of the generalized pairing Hamiltonian, the atomic nucleus is a system with small entanglement and can thus be described efficiently using a 1D tensor network (matrix-product state) despite the presence of long-range interactions. The ground state can be obtained using the density-matrix renormalization group (DMRG) algorithm, which is accurate up to machine precision even for large nuclei, is numerically as cheap as the widely used Bardeen-Cooper-Schrieffer (BCS) approach, and does not suffer from any mean-field artifacts. This framework is applied to compute the even-odd mass differences of all known lead isotopes from $��{}^{178}�\text{Pb}�$ to $��{}^{220}�\text{Pb}�$ in a very large configuration space of 13 shells between the neutron magic numbers 82 and 184 (i.e., two major shells) and find good agreement with the experiment. Pairing with non-zero angular momentum is also considered and the lowest excited states in the full configuration space of one major shell is determined, which is demonstrated for the $��N�=�126�$, $��Z�\ge �82�$ isotones. To demonstrate the capabilities of the method beyond low-lying excitations, the first 100 excited states of $��{}^{208}�\text{Pb}�$ with singlet pairing and the two-neutron removal spectral function of $��{}^{}$