The cover illustrates a structured optical field, dubbed a flower-shaped optical vortex array by Xinzhong Li and co-workers in article number 2000575. The inner layer uses a clock to represent the phase change, the hour hand represents the phase of the even IG beam, and the minute hand represents the phase of the odd IG beam. The outer layer is a specific example of an optical field, which keeps the phase of the odd IG beam unchanged, and changes the phase of the even IG beam, As the phase difference between the even mode IG beam and the odd mode IG beam increases, the optical field rotates gradually.

The distribution and generation of quantum coherence for the bipartite and tripartite Gaussian states in de Sitter space are discussed. It is shown that the curvature parameter and the mass parameter of the de Sitter space affect the coherence between Gaussian states, even if the observers are localized in causally disconnected regions.

A theory of light–matter interaction in plasmonic nanofibers doped with metallic nanoparticles (MNP) and quantum emitters (QEs) is presented. MNPs and QEs interact with each other via the dipole–dipole interaction (DDI). It is found that the quenching of the photoluminescence in the QE is because of the DDI. This finding can be used to fabricate random lasers, nanosensors and nanoswitches.

In a heterojunction formed by two types of nodal-line semimetals, quantum transmission is efficiently modulated when the barrier region demonstrates different energy-band properties. This is manifested as the appearance of antiresonance points or one gap in the transmission spectra, determined by the relation between the barrier and basal planes. Additionally, Klein tunneling displays new characteristics in this heterojunction.

In this article, a novel method is proposed to generate and shape tri-photon entanglement in the temporal domain via simplified single step of six-wave mixing processes of hot atomic gas media. The effect of three different kinds of dressing fields on shaping the tri-photon temporal waveform and the transition of nonlinear optical response to linear optical response are concentrated upon.

A scheme for achieving nonreciprocal-amplified signal transmission is proposed in a coupled rotation-cavity system. The Sagnac effect results in the nonreciprocal transmission. Due to the introduction of the optical parametric amplifier, eigenvalues present exceptional points, and unidirectional signal amplification can be realized in opposite propagating directions around exceptional points.

Here, an entanglement measure is built from measures for pure states. Conditions when the entanglement measure is entanglement monotone, convex, are presented as well as the interpretation of the smoothed one-shot entanglement cost. Then the extension of geometric entanglement measure and concurrence is considered. It is also shown that the measure is monogamous for $2\otimes 2\otimes d$ systems.

This work reports on a flower-shaped optical vortex array (FOVA) generated by the superposition of even and odd Ince–Gaussian (IG) beams. The number and sign of optical vortices (OVs) in the FOVA are controllable. This work has potential significance in applications such as micro-particle manipulation and optical measurements.

The partially coherent dual and quad Airy-like beams are investigated by introducing the coordinate transformation parameters and combining with the theory of multi-beams superposition. Both the optical frame and the interference pattern can be changed by adjusting the coordinate transformation parameters. Moreover, the peak of the spectral density and the divergence speed are controlled by the equivalent beam width.

It is shown that under the joint action of both Unruh effect and local environments, the N-qubit W state has all orders of coherence (from bipartite to N-partite subsystems), and the total coherence of any subsystem equals the sum of all the bipartite coherences in the subsystem. However, the N-qubit GHz state has only genuine global coherence.

A scheme to realize robust photon state transfer in a universal cavity optomechanical system by combining shortcuts to adiabaticity with optimal control technique is proposed. The optimized scheme is insensitive to deviations in optomechanical coupling and frequency detuning over a broad range. The effects of dissipation-induced decoherence on the transfer fidelity are discussed in detail.

In this article, a novel method is proposed to directly generate three-mode entanglement beams by using energy level cascaded FWM process in a single Rb vapor. Two generation paths are used, that is, simultaneous generation and ordinal generation, to theoretically investigate two- and three-mode amplitude, phase quadrature squeezing and intensity difference squeezing.

Despite the importance of the s-wave scattering length (a) in quantum degenerate gases and precision tests of fundamental physics, accurately calculating a can be problematic. Relationships a versus binding energy (D₀) can be derived from numerical exact solutions of vibrational Schrödinger equations for a set of effective potential energy curves. The resulting relations appear highly independent of the underlying potential.