Mode Division Multiplexing

A cladding medium switching strategy is introduced in photonic integrated circuits for dynamically tunable mode conversions. By utilizing subwavelength grating-based coupled-waveguide systems, Hao Jia and co-workers elaborately engineer phase matching conditions under different cladding mediums, and realize multi-state mode conversion functionalities when specific coupling conditions are fulfilled. Such a mechanism paves the way for flexible and energy-efficient reconfigurable mode manipulation.

Entanglement is a genuine form of quantum correlation, which plays a pivotal role in characterizing collective phenomena, from topological order to criticality and beyond. Here, results about entanglement Hamiltonians—an operator-based characterization of entanglement—in many-body systems are reviewed, from field theory and statistical mechanics models, to recent applications in the context of quantum information and quantum simulation.

This work introduces the cladding medium switching strategy to subwavelength grating-based coupled-waveguide systems. By analyzing the phase matching conditions under different cladding mediums and elaborately designing the tunable waveguide dispersion characteristics, multi-state mode conversion functionalities can be realized when the coupling conditions are fulfilled. Flexible and energy-efficient tunability for mode manipulation is available by such a mechanism.

A tunable reflection phase retarder is investigated through an optimized arrangement of the magnetized plasma, dielectric, and nonlinear Kerr dielectric. When the electric field of the incident electromagnetic wave is parallel to the xoy plane and has an angle of 45° with the x- axis, the 180° or −180° phase delay of the reflected wave of the proposed structure is obtained and adjusted under reasonable parameters.

Ultrashort light pulses are measured in space and time without any need for an ultrashort probe event or a nonlinear-optical phenomenon, thus overturning a tenacious belief in ultrafast laser optics that such a feat is impossible. The trick is the use of an auxiliary electron beam that randomly samples the waveform directly via the elementary charges at attosecond time resolution.

Strange quark matter (SQM) is described as diquark matter consisting of [ud], [us], and [ss] diquark correlations. Under the influence of strong magnetic field in dense SQM, diquarks behave like composite fermions (quasiparticles). Thermodynamic properties and velocity of sound show interesting behavior. The diquark correlation lowers the binding energy of SQM making the system more stable.

A scheme is proposed to realize the non-classical correlation between magnons and photons in a cavity optomagnonic system, which supports both photon modes and a magnon mode. The result indicates that cavity optomagnonics can be a promising platform for studying magnon-based quantum information processing.

A quantum circuit of the controlled-unitary operation with side controlling on $$C^{2} \otimes C^{N}$$ system is designed by utilizing Cartan decomposition technique. The synthesis is extended to the unitary operations on $$C^{M} \otimes C^{N}$$ which are locally equivalent to diagonal unitary operations. Additionally, the possible Schmidt rank of these unitary operations is presented in detail.

The measurability of PT-moments (partial-transpose-moments) bridges the practical limitations of the PPT (positive-partial-transpose) criterion. This work describes the whole region composed of the second and third PT-moments, for all two-qubit states, and determines the entangled region. It provides an experimentally efficient separability criterion of two-qubit states. This criterion is also applied to several widely used states to characterize their entanglement.

Anisotropic multi-Weyl semimetals play host to various exotic tunneling phenomena. In this work, inspired by an analogy to the field of dynamical phase transitions, these tunneling phenomena are classified by the term tunneling phase diagrams. Most insights are gained for the minimal model of a quadratic, anisotropic multi-Weyl semimetal.

Optical non-reciprocity exists in the proposed multi-mode cavity optomechanical system due to the time-reversal symmetry breaking that originates from uneven radiation pressure force. Bidirectional non-reciprocal signal transmission can be controlled by the system parameters that are experimentally possible. This scheme may offer a foundation to quantum computer components such as all-optical diodes, optical transistors, and optical switches.

Nonlinear topological photonics attracts great interest and is rarely explored in the synthetic space. This work studies the role of nonlinear effects in affecting the edge modes in a photonic topological insulator including the frequency axis of light, which may be useful in the future exploring many-body physics in synthetic space.

One of the main results is that for non-null values of the interlayer potential difference, we observe suppression of conductance in the gap areas. Consequently, we see that there are more conductance peaks than indicated by studies found in the literature.

A new type of controllable self-focusing circular vortex Pearcey Gaussian beam, which can create an optical potential well with adjustable depth and width at the center of the beam by adjusting the coherent width and the number of topological charges, is introduced.

With doubled sensitivity, the thermodynamic gas-pressure standard based on temperature and electrical measurements as well as ab initio calculations of the thermophysical properties of helium is compared to the most accurate mechanical pressure standard. This stress test for theory and experiment is once again successful.

A parameter diagram in terms of the appearance of topological gapless edge modes for a topological superconductor is exhibited. Such a topological feature can also be reflected by the Pauli matrices and the dynamics in different aspects. But noise disturbs the dynamical features and leads to localization.

The conductance of the graphene wormhole for free case and in the presence of an Aharonov–Bohm-like magnetic field is investigated. For this purpose, the motion of massless fermions in the background of a catenoid metric is analyzed and discussed. The scattering states of the system are used to find approximate expressions for the conductance by means of the Landauer method.