As third-generation semiconductors, group-III nitrides are promising for high power electronic and optoelectronic devices because of their wide bandgap, high electron saturation mobility, and other unique properties. Inspired by the thickness dependent properties of two-dimensional (2D) materials represented by graphene, it is predicted that the 2D counterparts of group-III nitrides would have similar

Quasiparticles with fractional charge and fractional statistics are key features of the fractional quantum Hall effect. We discuss in detail the definitions of fractional charge and statistics and the ways in which these properties may be observed. In addition to theoretical foundations, we review the present status of the experiments in the area. We also discuss the notions of non-Abelian statistics

This article is an introduction to two research programs that are currently very active, the conformal bootstrap and scattering amplitudes. Rather than attempting full surveys, the emphasis is on common ideas and methods shared by these two seemingly very different programs. In both fields, mathematical and physical constraints are placed directly on the physical observables in order to explore the

Aggregation of molecules is a multi-molecular phenomenon occurring when two or more molecules behave differently from discrete molecules due to their intermolecular interactions. Moving beyond single molecules, aggregation usually demonstrates evolutive or wholly emerging new functionalities relative to the molecular components. Conjugated small molecules and polymers interact with each other, resulting

Charles Richter’s observation that ‘only fools and charlatans predict earthquakes,’ reflects the fact that despite more than 100 years of effort, seismologists remain unable to do so with reliable and accurate results. Meaningful prediction involves specifying the location, time, and size of an earthquake before it occurs to greater precision than expected purely by chance from the known statistics

Electron capture on nuclei plays an essential role in the dynamics of several astrophysical objects, including core-collapse and thermonuclear supernovae, the crust of accreting neutron stars in binary systems and the final core evolution of intermediate-mass stars. In these astrophysical objects, the capture occurs at finite temperatures and densities, at which the electrons form a degenerate relativistic

Fluids exhibit remarkable variation in their structural and dynamic properties when they are confined at the nanoscopic scale. Various factors, including geometric restriction, the size and shape of the guest molecules, the topology of the host, and guest–host interactions, are responsible for the alterations in these properties. Due to their porous structures, aluminosilicates provide a suitable host

Given its briefness and predictability, the minimal seesaw—a simplified version of the canonical seesaw mechanism with only two right-handed neutrino fields—has been studied in depth and from many perspectives, and now it is being pushed close to a position of directly facing experimental tests. This article is intended to provide an up-to-date review of various phenomenological aspects of the minimal

Given its briefness and predictability, the minimal seesaw-a simplified version of the canonical seesaw mechanism with only two right-handed neutrino fields-has been studied in depth and from many perspectives, and now it is being pushed close to a position of directly facing experimental tests. This article is intended to provide an up-to-date review of various phenomenological aspects of the minimal

Over the past decade, two-dimensional semiconductors (2DSCs) have aroused wide interest due to their extraordinary electronic, magnetic, optical, mechanical, and thermal properties, which hold potential in electronic, optoelectronic, thermoelectric applications, and so forth. The field-effect transistor (FET), a semiconductor gated with at least three terminals, is pervasively exploited as the device

I review the four mechanisms of bound states in the continuum (BICs) in the application of microwave and acoustic cavities open to directional waveguides. The most simple are symmetry-protected BICs, which are localized inside the cavity because of the orthogonality of the eigenmodes to the propagating modes of waveguides. However, the most general and interesting is the Friedrich–Wintgen mechanism

I review the four mechanisms of bound states in the continuum (BICs) in the application of microwave and acoustic cavities open to directional waveguides. The most simple are symmetry-protected BICs, which are localized inside the cavity because of the orthogonality of the eigenmodes to the propagating modes of waveguides. However, the most general and interesting is the Friedrich-Wintgen mechanism

We review the theoretical aspects relevant in the description of high-energy heavy ion collisions, with an emphasis on the learnings about the underlying quantum chromodynamics phenomena that have emerged from these collisions.

Aggregation of molecules is a multi-molecular phenomenon occurring when two or more molecules behave differently from discrete molecules due to their intermolecular interactions. Moving beyond single molecules, aggregation usually demonstrates evolutive or wholly emerging new functionalities relative to the molecular components. Conjugated small molecules and polymers interact with each other, resulting

The description of strong interaction physics of low-lying resonances is out of the valid range of perturbative QCD. Chiral effective field theories have been developed to tackle the issue. Partial wave dynamics is the systematic tool to decode the underlying physics and reveal the properties of those resonances. It is extremely powerful and helpful for our understanding of the non-perturbative regime

The description of strong interaction physics of low-lying resonances is out of the valid range of perturbative QCD. Chiral effective field theories have been developed to tackle the issue. Partial wave dynamics is the systematic tool to decode the underlying physics and reveal the properties of those resonances. It is extremely powerful and helpful for our understanding of the non-perturbative regime

Charles Richter's observation that "only fools and charlatans predict earthquakes," reflects the fact that despite more than 100 years of effort, seismologists remain unable to do so with reliable and accurate results. Meaningful prediction involves specifying the location, time, and size of an earthquake before it occurs to greater precision than expected purely by chance from the known statistics

Here we provide a comprehensive review of a newly developed lighting technology based on metal halide perovskites (i.e. perovskite light-emitting diodes) encompassing the research endeavours into materials, photophysics and device engineering. At the outset we survey the basic perovskite structures and their various dimensions (namely three-, two- and zero-dimensional perovskites), and demonstrate

An outstanding open issue in our quest for physics beyond Einstein is the unification of general relativity (GR) and quantum physics. Loop quantum gravity (LQG) is a leading approach toward this goal. At its heart is the central lesson of GR: gravity is a manifestation of spacetime geometry. Thus, the approach emphasizes the quantum nature of geometry and focuses on its implications in extreme regimes—near

Fluids exhibit remarkably different structural and dynamical properties when they are confined in nanoscopic regimes. Various factors including geometric restriction, size and shape of the guest molecules, topology of the host, guest-host interactions, are responsible for the alteration in these properties. Aluminosilicates, having porous structures, provide a suitable host system to study the diffusion

Near-field radiative heat transfer (NFRHT) governed by evanescent waves, provides a platform to thoroughly understand the transport behavior of nonradiative photons, and also has great potential in high-efficiency energy harvesting and thermal management at the nanoscale. It is more usual in nature that objects participate in heat transfer process in many-body form rather than the frequently-considered

The goal of immunotherapy is to mobilize the immune system to kill cancer cells. Immunotherapy is more effective and, in general, the prognosis is better, when more immune cells infiltrate the tumor. We explore the question of whether the spatial distribution rather than just the density of immune cells in the tumor is important in forecasting whether cancer recurs. After reviewing previous work on

Wide bandgap semiconductor aluminum gallium nitride (AlGaN) alloys have established themselves as the key materials for building ultraviolet (UV) optoelectronic and power electronic devices. However, further improvements of device performance are lagging behind largely due to the difficulties in precisely controlling the carrier behavior, both carrier generation and carrier transport within the AlGaN-based

Jet quenching has been used successfully as a hard probe to study properties of the quark-gluon plasma (QGP) in high-energy heavy-ion collisions at both the relativistic heavy-ion collider and the large hadron collider. We will review recent progresses in theoretical and phenomenological studies of jet quenching with jet transport models. Special emphasis is given to effects of jet-induced medium response

Recently, the emerging conceptual valley-related devices have attracted much attention due to the progress on generating, controlling, and detecting the valley degree of freedom in the transition metal dichalcogenide (TMD) monolayers. In general, it is known that achieving valley degree of freedom with long valley lifetime is crucial in the implementation of valleytronic devices. Here, we provide a

The introduction of engineered resonance phenomena on surfaces has opened a new frontier in surface science and technology. Pillared phononic crystals, metamaterials, and metasurfaces are an emerging class of artificial structured media, featuring surfaces, that consist of pillars-or branching substructures-standing on a plate or a substrate. A pillared phononic crystal exhibits Bragg band gaps while

Photoacoustic computed tomography (PACT) is a novel biomedical imaging modality and has experienced fast developments in the past two decades. Spatial resolution is an important criterion to measure the imaging performance of a PACT system. Here we survey state-of-the-art literature on the spatial resolution of PACT and analyze resolution degradation models from signal generation, propagation, reception

Quantum fluctuations can stabilize Bose-Einstein condensates (BEC) against the mean-field collapse. Stabilization of the condensate has been observed in quantum degenerate Bose-Bose mixtures and dipolar BECs. The fine-tuning of the interatomic interactions can lead to the emergence of two new states of matter: liquid-like selfbound quantum droplets and supersolid crystals formed from these droplets

Nearly 30 years ago, Hong, Ou and Mandel observed what Richard Feynman referred to as "The heart of quantum mechanics": the two-photon interference effect. This observation marked the beginning of a new quantum era, where the peculiarity of quantum physics may now be used to our advantage to outperform classical computations, securely communicate information, simulate highly complex physical systems

Artificial intelligence (AI) is the most important new methodology in scientific research since the adoption of quantum mechanics and it is providing exciting results in numerous fields of science and technology. In this review we summarize research and discuss future opportunities for AI in the domains of photonics, nanophotonics, plasmonics and photonic materials discovery, including metamaterials

The walking droplet system discovered by Yves Couder and Emmanuel Fort presents an example of a vibrating particle self-propelling through a resonant interaction with its own wave field. It provides a means of visualizing a particle as an excitation of a field, a common notion in quantum field theory. Moreover, it represents the first macroscopic realization of a form of dynamics proposed for quantum

Metasurfaces are artificial two-dimensional (2D) planar surfaces that consist of subwavelength 'meta-atoms' (i.e. metallic or dielectric nanostructures). They are known for their capability to achieve better and more efficient light control in comparison to their traditional optical counterparts. Abrupt and sharp changes in the electromagnetic properties can be induced by the metasurfaces rather than

Colloidal particles can be adsorbed at fluid-fluid interfaces, a phenomenon frequently observed in particle-stabilized foams, Pickering emulsions, and bijels. Particles adsorbed at interfaces exhibit unique physical and chemical behaviors, which affect the mechanical properties of the interface. Therefore, interfacial colloidal particles are of interest in terms of both fundamental and applied research

With the advent of a new generation of neutrino experiments which leverage high-intensity neutrino beams for precision neutrino oscillation parameter and for CP violation phase measurements, it is timely to explore physics topics beyond the standard neutrino-related physics. Given that beyond the standard model (BSM) physics phenomena have been mostly sought at high-energy regimes, such as the LHC

This review treats asymmetric colloidal particles moving through their host fluid under the action of some form of propulsion. The propulsion can come from an external body force or from external shear flow. It may also come from externally-induced stresses at the surface, arising from imposed chemical, thermal or electrical gradients. The resulting motion arises jointly from the driven particle and

Single-shot coded-aperture optical imaging physically captures a code-aperture-modulated optical signal in one exposure and then recovers the scene via computational image reconstruction. Recent years have witnessed dazzling advances in various modalities in this hybrid imaging scheme in concomitant technical improvement and widespread applications in physical, chemical and biological sciences. This

Mode-locking lasers have not only produced huge economic benefits in industrial fields and scientific researches, but also provided an excellent platform to study diverse soliton phenomena. However, the real-time characterization of the ultrafast soliton dynamics remains challenging for the traditional electronic instruments due to their relatively little response bandwidth and slow scan rate. Consequently

Pseudo-relativistic chiral electrons in 2D graphene and 3D topological semimetals, known as massless Dirac or Weyl fermions, constitute various intriguing topics in modern condensed-matter physics. Among these electron-electron Coulomb-interaction effects are particularly unique and attract great attentions since the interaction between the chiral electrons is not screened and remains long-ranged,

The extended Burgers model (EBM) provides a linear viscoelastic theory for interpreting a variety of rock deformation phenomena in geophysics, playing an increasingly important role in parameterizing laboratory data, providing seismic wave velocity and attenuation interpretations, and in analyses of solid planetary tidal dispersion and quality factor Q. At the heart of the EBM approach is the assumption

Humankind has been obsessed with knots in religion, culture and daily life for millennia while physicists like Gauss, Kelvin and Maxwell involved them in models already centuries ago. Nowadays, colloidal particle can be fabricated to have shapes of knots and links with arbitrary complexity. In liquid crystals, closed loops of singular vortex lines can be knotted by using colloidal particles and laser

Through the years, mineralogical studies have produced a tremendous amount of data on the atomic arrangement and mineral properties. Quite often, structural analysis has led to elucidate the role played by minor components, giving interesting insights into the physico-chemical conditions of minerals and allowing the description of unpredictable structures that represented a body of knowledge critical

Dripping, jetting and tip streaming have been studied up to a certain point separately by both fluid mechanics and microfluidics communities, the former focusing on fundamental aspects while the latter on applications. Here, we intend to review this field from a global perspective by considering and linking the two sides of the problem. In the first part, we present the theoretical model used to study

Fourier ptychographic microscopy (FPM) is a promising and fast-growing computational imaging technique with high resolution (HR), wide field-of-view (FOV) and quantitative phase recovery, which effectively tackles the problems of phase loss, aberration-introduced artifacts, narrow depth-of-field (DOF) and the trade-off between resolution and FOV in conventional microscopy simultaneously. In this review

Determining the inner structure of protons and nuclei in terms of their fundamental constituents has been one of the main tasks of high energy nuclear and particle physics experiments. This quest started as a mapping of the (average) parton densities as a function of longitudinal momentum fraction and resolution scale. Recently, the field has progressed to more differential imaging, where one important

Rooted in quantum optics and benefiting from its well-established foundations, strong coupling in nanophotonics has experienced increasing popularity in recent years. With nanophotonics being an experiment-driven field, the absence of appropriate theoretical methods to describe ground-breaking advances has often emerged as an important issue. To address this problem, the temptation to directly transfer

Metal halide perovskites having three-dimensional crystal structures have already been applied successfully in various optoelectronic applications. To address their most challenging issues-instability and toxicity-without losing efficiency, lower-dimensional perovskites appear to be promising alternatives. Recently, two-dimensional (2D) perovskite solar cells have been developed exhibiting excellent

Light absorption generates strongly bound excitons in organic solar cells (OSCs). To obtain efficient charge generation, a large driving force is required, which causes a large energy loss (Eloss) and severely hinders the improvement in the power conversion efficiencies (PCEs) of OSCs. Recently, the development of non-fullerene OSCs has seen great success, and the resulting OSCs can yield highly efficient

From our own experience in the group, we know that there is quite a gap to bridge between scientists focused on basic material research and their counterparts in a close-to-application community focused on identifying and solving final technological and engineering challenges. In this review, we try to provide an easy-to-grasp introduction to the field of memory technology for materials scientists

This review article presents the progress made over the last decade, since the introduction of effective field theories (EFTs) into post-Newtonian (PN) Gravity. These have been put forward in the context of gravitational waves (GWs) from the compact binary inspiral. The mature development of this interdisciplinary field has resulted in significant advances of wide interest to physics at several levels

This paper reviews optical fibre technology for local area optical communications systems. Technologies used in local systems include single and multimode fibre, single and multimode lasers, optical modulators, photodetectors, wavelength division multiplexing, multilevel modulation formats, electronic packet switching, electronic equalization and error correction. These methods have enabled the local

The frontier of low-temperature physics has advanced to the mid pico-Kelvin (pK) regime but progress has come to a halt because of the problem of gravity. Ultra cold atoms must be confined in some type of potential energy well: if the depth of the well is less than the energy an atom gains by falling through it, the atom escapes. This article reviews ultra cold atom research, emphasizing the advances

We review the binding and energy level alignment of π-conjugated systems on metals, a field which during the last two decades has seen tremendous progress both in terms of experimental characterization as well as in the depth of theoretical understanding. Precise measurements of vertical adsorption distances and the electronic structure together with ab-initio calculations have shown that most of the

From its seemingly non-intuitive and puzzling nature, most evident in numerous EPR-like gedankenexperiments to its almost ubiquitous presence in quantum technologies, entanglement is at the heart of modern quantum physics. First introduced by Erwin Schrödinger nearly a century ago, entanglement has remained one of the most fascinating ideas that came out of quantum mechanics. Here, we attempt to explain

The high sensitivity detection of terahertz radiation is crucial for many chemical sensing, biomedical imaging, security screening, nondestructive quality control, high-data-rate communication, atmospheric, and astrophysics sensing applications. Among various terahertz detection techniques, heterodyne detection is of great interest for applications that require high spectral resolution. Heterodyne

Inspired by the success of graphene, various two dimensional (2D) non-hexagonal graphene allotropes having sp 2 bonded tetragonal rings in free standing (FS) (hypothetical) form and on different substrates have been proposed recently. These systems have also been fabricated after modifying the topology of graphene by chemical processes. In this review, we would like to in- dicate the role of tetra-rings

Quantum annealing is a computing paradigm that has the ambitious goal of efficiently solving large-scale combinatorial optimization problems of practical importance. However, many challenges have yet to be overcome before this goal can be reached. This perspectives article first gives a brief introduction to the concept of quantum annealing, and then highlights new pathways that may clear the way towards

Infrared detection and imaging are key enabling technologies for a vast number of applications, ranging from communication, to medicine and astronomy, and have recently attracted interest for their potential application in optical interconnects and quantum computing. Nonetheless, infrared detection still constitutes the performance bottleneck for several of these applications, due to a number of unsolved

Direct real photons are arguably the most versatile tools to study relativistic heavy ion collisions. They are produced, by various mechanisms, during the entire space-time history of the strongly interacting system. Also, being colorless, most the time they escape without further interaction, \ie they are penetrating probes. This makes them rich in information, but hard to decypher and interpret.

Natural visual systems have inspired scientists and engineers to mimic their intriguing features for the development of advanced photonic devices that can provide better solutions than conventional ones. Among various kinds of natural eyes, researchers have had intensive interest in mammal eyes and compound eyes due to their advantages in optical properties such as focal length tunability, high-resolution

This report summarizes progress made in understanding properties such as zero-phonon-line energies, emission and absorption polarizations, electron-phonon couplings, strain tuning and hyperfine coupling of single photon emitters in hexagonal boron nitride. The primary aims of this research are to discover the chemical nature of the emitting centres and to facilitate deployment in device applications