Wavelength-Scale Singlet Achromatic Microlens

A traditional lens is usually bulky and heavy for it is a combination of several designed lenses to correct the chromatic aberration. A metalens is based on the achromatic phase response of the nanostructures, which can exhibit an excellent achromatic performance in a wavelength-level thickness, however, relies on nano-fabrication. In article number 2300543, Yang Bai, Jingbo Sun, and co-workers propose a general design principle to develop a microlens with high-index materials with both the achromatic performance and a small thickness.

Photon Blockades in an Optomechanical Cavity

In article number 2300465, Le-Man Kuang and co-workers study the photon blockades in an optomechanical cavity with a BoseEinstein condensate. By tuning the interatomic scattering strength, a switch between single-photon blockade and photon-induced tunneling can be realized, and the enhancement of single-photon blockade can be achieved in both interatomic repulsion and attraction conditions. Moreover, the system can exhibit stronger single-photon blockade under the same optomechanical coupling than a conventional optomechanical system.

The research on Artificial Saturable Absorber (ASA) based 2 $$\umu {\rm m}$$ ultrafast fiber lasers insurged in the past decade. This work offers a comprehensive review on the works done in the same field and an in-depth analysis of the theory of each ASA method.

A method is proposed to achieve the singlet achromatic microlens of the wavelength-scale thickness by utilizing high refractive index materials with an aspherical profile. Accordingly, three materials with different degrees of refractive index and dispersion are selected to prepare achromatic microlenses. The results demonstrate all achieving achromatic limiting focus. Moreover, the thickness of the high-index microlens is only 573 nm, a reduction of ≈50% compared to the low-index microlens.

This paper studies the photon blockades in an optomechanical cavity with a Bose-Einstein Condensate. By tuning interatomic scattering strength, the switch between single-photon blockade and photon-induced tunneling and the enhancement of single-photon blockade can be realized in interatomic repulsion or attraction conditions. Moreover, the system can exhibit the stronger 1PB under the same optomechanical coupling than conventional optomechanical system.

Entropic uncertainty relations (EURs) are inequalities that express preparation uncertainty as sums of Shannon entropies of probability distributions of measurement outcomes. The additivity properties of EURs for joint Shannon entropies of probabilities of local measurement outcomes with bipartite and multipartite systems and investigate the relation between uncertainty and quantum correlations is studied. Hence, new criteria for separability are found.

This article introduces a novel optoelectronic neural network utilizing a metasurface encoder for real-time multimodal brain image segmentation. The network dramatically enhances computing speed and reduces costs, employing multi-layer metasurfaces for pre-processing, optimizing image dimensionality and improving diagnostic processes for brain tumors.

The dynamic behavior of atomic bonding and electron states at singular points in Ba₂ScNbO₆ and Ba₂LuNbO₆ non-Hermitian systems is investigated.

A weak-measurement-based entanglement protection is proposed in this article. Compared to directly sending the quantum state $$\rho _{0}$$ into the channel, the state is “pushed” close to a decoherence-free state by weak measurement to reduce the decoherence. After the channel, the initial state can be retrieved by another weak measurement.

The coupling of an Andreev molecule to a topological superconducting nanowire, hosting Majorana quasiparticles at its ends, generates additional states in quantum dots. Transport measurements allow for the observation of the leakage of Majorana quasiparticles into the double dot system. Additionally, nonlocal pairing of electrons with parallel spins can be observed in the analyzed system.

The intrinsic decoherence refers to the loss of quantum coherence between the superposed states of a system, usually induced by interactions with the external environment. This can cause quantum phenomena such as interference and superposition to disappear, leading to unpredictable evolution of the system.

TlBi₂ is an intriguing superconductor with heavy elements for two main reasons. First, its high mass elements with 6p electrons suggest SOC could influence its physical properties. Second, it crystallizes in the hexagonal AlBi₂-type layer structure, like MgB₂, known for its high T_c. Various properties of TlBi₂ are investigated using first-principles calculations based on density functional theory, with and without SOC.

This study investigates a weak force sensing scheme in a cavity optomechanical system using a degenerate optical parametric amplifier (OPA) and an auxiliary oscillator to suppress quantum noise. It demonstrates that noise reduction in coupled oscillators relies on their normal mode splitting. Additionally, the OPA mechanism enhances cavity field squeezing and photon number fluctuation reduction. This new design offers insights into deeper applications of cavity field squeezing and auxiliary oscillators in force sensing.

The geometry of wormholes in galactic halos due to dark matter has been explored using 4D EGB gravity. The images describe the behavior of these wormholes, which clearly meet the traversability conditions. The study confirms that the wormhole solutions obtained may exist in the galactic halos within the framework of 4D EGB gravity.