Man-Hong Wong

Bio: Man-Hong Wong is an academic researcher from University of Illinois at Urbana–Champaign. The author has contributed to research in topics: Angle-resolved photoemission spectroscopy & Topological insulator. The author has an hindex of 3, co-authored 5 publications receiving 117 citations.

Elemental Topological Dirac Semimetal: α -Sn on InSb(111)

Abstract: Three-dimensional (3D) topological Dirac semimetals (TDSs) are rare but important as a versatile platform for exploring exotic electronic properties and topological phase transitions. A quintessential feature of TDSs is 3D Dirac fermions associated with bulk electronic states near the Fermi level. Using angle-resolved photoemission spectroscopy, we have observed such bulk Dirac cones in epitaxially grown α-Sn films on InSb(111), the first such TDS system realized in an elemental form. First-principles calculations confirm that epitaxial strain is key to the formation of the TDS phase. A phase diagram is established that connects the 3D TDS phase through a singular point of a zero-gap semimetal phase to a topological insulator phase. The nature of the Dirac cone crosses over from 3D to 2D as the film thickness is reduced.

Surface Collective Modes in the Topological Insulators Bi_{2}Se_{3} and Bi_{0.5}Sb_{1.5}Te_{3-x}Se_{x}.

Abstract: We used low-energy, momentum-resolved inelastic electron scattering to study surface collective modes of the three-dimensional topological insulators Bi_{2}Se_{3} and Bi_{0.5}Sb_{1.5}Te_{3-x}Se_{x}. Our goal was to identify the "spin plasmon" predicted by Raghu and co-workers [Phys. Rev. Lett. 104, 116401 (2010)]. Instead, we found that the primary collective mode is a surface plasmon arising from the bulk, free carriers in these materials. This excitation dominates the spectral weight in the bosonic function of the surface χ^{"}(q,ω) at THz energy scales, and is the most likely origin of a quasiparticle dispersion kink observed in previous photoemission experiments. Our study suggests that the spin plasmon may mix with this other surface mode, calling for a more nuanced understanding of optical experiments in which the spin plasmon is reported to play a role.

Spectroscopic studies of CdTe ( 111 ) bulk and surface electronic structure

Abstract: Cadmium telluride (CdTe) is a direct band-gap semiconducting material with broad applications in optoelectronic devices. Here we report on a high-resolution angle-resolved photoemission (ARPES) study of $\mathrm{CdTe}(111)$ surfaces prepared by sputtering and annealing that show a $(2\ifmmode\times\else\texttimes\fi{}2)$ reconstruction as observed by electron diffraction. The ARPES maps along high-symmetry directions show prominent features with their intensities modulated by varying the incident photon energy, thus suggesting important matrix element effects associated with photoemission. The results are in excellent agreement with first-principles calculations of the bulk band structure and one-dimensional density of states. A prominent surface state is observed that exhibits a $(2\ifmmode\times\else\texttimes\fi{}2)$ periodicity in agreement with the symmetry of the surface reconstruction.

Observation of a Smoothly Tunable Dirac Point in $Ge(Bi_{x}Sb_{1-x})_{2}Te_{4}$.

Abstract: State-of-the-art topological devices require the use topological surface states to drive electronic transport. In this study, we examine a tunable topological system, $Ge(Bi_{x}Sb_{1-x})_{2}Te_{4}$, for a range of 'x' values from 0 to 1, using a combination of Fourier Transform Scanning Tunneling Spectroscopy (FT-STS) and Angle-Resolved Photoemission Spectroscopy (ARPES). Our results show that the Dirac point shifts linearly with 'x', crossing the Fermi energy near x = 0.7. This novel observation of a smoothly tunable, isolated Dirac point crossing through the topological transport regime and having strong linear dependence with substitution can be critical for future topological spintronics applications.

Polaritons in van der Waals materials

Abstract: BACKGROUND Light trapped at the nanoscale, deep below the optical wavelength, exhibits an increase in the associated electric field strength, which results in enhanced light-matter interaction. This leads to strong nonlinearities, large photonic forces, and enhanced emission and absorption probabilities. A practical approach toward nanoscale light trapping and manipulation is offered by interfaces separating media with permittivities of opposite signs. Such interfaces sustain hybrid light-matter modes involving collective oscillations of polarization charges in matter, hence the term polaritons. Surface plasmon polaritons, supported by electrons in metals, constitute a most-studied prominent example. Yet there are many other varieties of polaritons, including those formed by atomic vibrations in polar insulators, excitons in semiconductors, Cooper pairs in superconductors, and spin resonances in (anti)ferromagnets. Together, they span a broad region of the electromagnetic spectrum, ranging from microwave to ultraviolet wavelengths. We discuss polaritons in van der Waals (vdW) materials: layered systems in which individual atomic planes are bonded by weak vdW attraction (see the figure). This class of quantum materials includes graphene and other two-dimensional crystals. In artificial structures assembled from dissimilar vdW atomic layers, polaritons associated with different constituents can interact to produce unique optical effects by design. ADVANCES vdW materials host a full suite of different polaritonic modes with the highest degree of confinement among all known materials. Advanced near-field imaging methods allow the polaritonic waves to be launched and visualized as they travel along vdW layers or through multilayered heterostructures. Spectroscopic and nanoimaging experiments have identified multiple routes toward manipulation of nano-optical phenomena endowed by polaritons. A virtue of polaritons in vdW systems is their electrical tunability. Furthermore, in heterostructures assembled from dissimilar vdW layers, different brands of polaritons interact with each other, thus enabling unparalleled control of polaritonic response at the level of single atomic planes. New optoelectronic device concepts aimed at the detection, harvesting, emission, propagation, and modulation of light are becoming feasible as a result of combined synthesis, nanofabrication, and modeling of vdW systems. The extreme anisotropy of vdW systems leading to opposite signs of the in-plane and out-of-plane permittivities of the same layered crystal enables efficient polaritonic waveguides, which are instrumental for subdiffractional focusing and imaging. In addition to near-field optical probes facilitating nanoimaging, coupling to polaritons can be accomplished via electrical excitation and nonlinear wave mixing. OUTLOOK Potential outcomes of polariton exploration in vdW heterostructures go beyond nano-optical technologies. In particular, images of polaritonic standing and traveling waves contain rich insights into quantum phenomena occurring in the host material supporting polaritons. This line of inquiry into fundamental physics through polaritonic observations constitutes an approach toward optics-based materials research. In particular, the strong spatial confinement exhibited by vdW polaritons involves large optical-field gradients—or equivalently, large momenta—which allows regions of the dispersion relations of electrons, phonons, and other condensed-matter excitations to be accessed beyond what is currently possible with conventional optics. Additionally, polaritons created by short and intense laser pulses add femtosecond resolution to the study of these phenomena. Alongside future advances in the understanding of the physics and interactions of vdW polaritons, solutions to application challenges may be anticipated in areas such as loss compensation, nanoscale lasing, quantum optics, and nanomanipulation. The field of vdW polaritonics is ripe for exploring genuinely unique physical scenarios and exploiting these new phenomena in technology. van der Waals (vdW) materials consist of individual atomic planes bonded by weak vdW attraction. They display nearly all optical phenomena found in solids, including plasmonic oscillations of free electrons characteristic of metals, light emission/lasing and excitons encountered in semiconductors, and intense phonon resonances typical of insulators. These phenomena are embodied in confined light-matter hybrid modes termed polaritons—excitations of polarizable media, which are classified according to the origin of the polarization. The most studied varieties are plasmon, phonon, and exciton polaritons. In vdW materials, polaritons exhibit extraordinary properties that are directly affected by dimensionality and topology, as revealed by state-of-the-art imaging of polaritonic waves. vdW heterostructures provide unprecedented control over the polaritonic response, enabling new quantum phenomena and nanophotonics applications.

Journal of Physics B: atomic, molecular and optical physics

Abstract: Journal of Applied Spectroscopy | HomeNuclear Instruments and Methods in Physics Research Atomic Physics authors/titles recent submissionsHome IOP PublishingPhysics Reports Journal ElsevierJournal WikipediaApplied Physics B | HomeThe European Physical Journal D (EPJ D)Chinese Physics B IOPscienceUkrainian Journal of PhysicsJournal of the Optical Society of America B JOSA BInternational Journal of Modern Physics B World ScientificJournal rankings for ARC, all 01* categories sorted Physics WikipediaInternational Scholarly Research Notices | HindawiAbbreviations A B Bioscience Journal Abbreviations Physical Review BEPJ European Physical JournalJournal of Vacuum Science & Technology BScitation HomeInternational Journal of Modern Physics E World ScientificJournal of Physics B: Atomic, Molecular and Optical The European Physical Journal B (EPJ B)Physical Review AAuthors Scientific Papers GS JournalJournal of Physics: Conference Series Latest Impact Factor Canadian Journal of Physics Canadian Science PublishingNuclear Physics B | Journal | ScienceDirect.com by Elsevier International Journal of Modern Physics E. Nuclear Physics. ISSN (print): 0218-3013 | ISSN (online Polarizability effects in atomic nuclei J. N. Orce Vol to provide the scientific background for future joint projects between the experts from these diverse areas in hadron physics. (Read full article.) Neutron star equations of state and GS Journal is your leading platform for high quality science journals, scientific papers and peer-reviewed full-text journals />07-12-2021 � The European Physical Journal D (EPJ D) presents new and original research results in Atomic, Molecular, Optical and Plasma Physics29-11-2021 � Editors' Choice Canadian Journal of Physics Cross sections and ionization rates are atomic data that have important applications in astrophysics and plasma physics. This work aims to calculate the electron impact ionization cross sections of some helium-like ions using the relativistic distorted wave method implemented in Flexible Atomic Code.Nuclear Physics B focuses on the domain of high energy physics, quantum field theory, statistical systems, and mathematical physics, and includes four main sections: high energy physics phenomenology, high energy physics theory, high energy physics experiment, and quantum field theory, ⋯. Read more18-08-2021 � Title abbreviations for journals in the areas of biology and chemistry. Bioscience journal title abbreviations A B.The American Physical Society (APS) is delighted to announce the appointment of David Scanlon, Professor of Computational Materials Design, University College of London, United Kingdom, to the role of Lead Editor of PRX Energy, APS’s new, highly selective, open access journal covering energy science and technology.Professor Scanlon will serve as the inaugural Lead Editor of ⋯15-12-2021 � Journal Impact IF Ranking � In the Physics and Astronomy (all) research field, the Quartile of Journal of Physics: Conference Series is Q4. Journal of Physics: Conference Series has been ranked #191 over 233 related journals in the Physics and Astronomy (all) research category. The ranking percentile of Journal of Physics: Conference Series is ⋯30-11-2021 � 14-b Metrolohichna str., Kyiv, Ukraine, 03028 Tel: +380(44) 521-31-88 E-mail: ujp@bitp.kiev.ua Scope: Ukrainian Journal of Physics is the general physics edition of the Department of Physics and Astronomy of the National Academy of Sciences of Ukraine.Journal Rankings proposed by the Austral. Math. Society, FoR codes 01*15-10-2021 � Journal of Vacuum Science and Technology B is an interdisciplinary journal focused on nanotechnology and microelectronic devices and processing, devoted to publishing reports of original research, letters, and review articles.Journal of Applied Physics Aug 23 2016. Shaping the Understanding the nature of the forces that both control and result from the molecular and atomic arrangements in matter will help shed light on chemical interactions in nature and can therefore lead to cures for disease.Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. Physics is one of the most fundamental scientific disciplines, and its main goal is to understand how the universe behaves.. Physics is one of the oldest academic disciplines and, through its inclusion of ⋯Chinese Physics B is an international journal covering the latest developments and achievements in all branches of physics (with the exception of nuclear physics and physics of elementary particles and fields, which is covered by Chinese Physics C).Topic Scope: JOSA B emphasizes scientific research on the fundamentals of the interaction of light with matter such as quantum optics, nonlinear optics, and laser physics. Topics include atom optics and cold atoms, integrated and fiber optics, metamaterials, nanophotonics, photonic crystals, photorefractive optics and holography, physics of optical materials, spectroscopy, ⋯Journal of Physics B: Atomic, Molecular and Optical Physics covers the study of atoms, ions, molecules and clusters, and their structure and interactions with particles, photons or fields. Submit an article opens in new tab Track my article opens in new tab. RSS. Sign up for Phys. Rev. B 104, 174443 (2021) Quantized phase-coherent heat transport of counterpropagating Majorana modes Alexander G. Bauer et al. Phys. Rev. B 104, L201410 (2021) Soft-mode anisotropy in the negative thermal expansion material ReO 3 Tobias A. Bird et al. Phys. Rev. B 104, 214102 (2021) Critical drag as a mechanism for resistivityInternational Journal of Modern Physics B Condensed Matter Physics; Statistical Physics; Atomic, Molecular and Optical Physics ISSN (print): 0217-9792 | ISSN (online): 1793-6578We publish academic journals, as well as books and conference proceedings. All our academic publications are hosted on IOPscience, a platform specifically designed to help readers access scientific, technical and medical content quickly and easily.. We also provide expert science journalism through Physics World, a trusted source of science news.04-11-2021 � Journal of Applied Spectroscopy reports on key applications of spectroscopy in, physics, chemistry , material science, medicine, biology, ecology and spectral instrument-industry . An increasing number of papers presented here focus on the theory of lasers, as well as on the tremendous potential for the practical applications of lasers in numerous fields and industries.A journal, from the Old French journal (meaning "daily"), may refer to: . Bullet journal, a method of personal organizations; Diary, a record of what happened over the course of a day or other period; Daybook, also known as a general journal, a daily record of financial transactions; Logbook, a record of events important to the operation of a vehicle, facility, or otherwise29-11-2021 � EPJ B Topical Issue: Recent developments in the functional renormalization group approach to correlated electron systems ; EPJ D Topical Issue: Advances in Multi-Scale Modelling of Intense Electronic Excitation Processes ; EPJ D Topical Issue: Atomic, Molecular and Optical Techniques for Fundamental PhysicsInternational Journal of Differential Equations. Journal metrics. Acceptance rate 25%. Submission to final decision 46 days. Acceptance to publication 47 days. CiteScore 1.900. Journal Citation Indicator 0.520. Impact Factor-APC $1025. International Journal of Microbiology. Journal metrics.14-12-2021 � Publishing essential research results in two of the most important areas of applied physics, both Applied Physics sections figure among the top most cited journals in this field. In addition to regular papers Applied Physics B: Lasers and Optics features invited reviews. Fields of topical interest are covered by feature issues.02-05-2017 � Physics Reports keeps the active physicist up-to-date on developments in a wide range of topics by publishing timely reviews which are more extensive than just literature surveys but normally less than a full monograph. Each report deals with one specific subject and is generally published in a separate volume. These reviews are specialist in nature but contain ⋯NIMB or Section B of Nuclear Instruments and Methods in Physics Research covers all aspects of the interaction of energetic beams with atoms, molecules and aggregate forms of matter. This includes ion beam analysis and ion beam modification of materials as well as basic data of importance for ⋯ Read more13-11-2021 � The European Physical Journal B Statistical and Nonlinear Physics First-passage time and change of entropy. V. V. Ryazanov. Eur. Phys. J. B, 94 12 (2021) 242. Published online: 11 December 2021. DOI: 10.1140/epjb/s10051 12th International Conference on Atomic and Molecular Data and Their Applications 25-29 September 2022 12-08-2021 � Subjects: Atomic Physics (physics.atom-ph); Chemical Physics (physics.chem-ph); Quantum Physics (quant-ph) [8] arXiv:2108.05996 [ pdf , other ] Title: Ultracold $^{88}\rm{Sr}_2$ molecules in the absolute ground state Copyright code : f0a76c2d68cb7e7cb469c606fb9f8c72

Chemical Principles of Topological Semimetals

Abstract: Initiated by the discovery of topological insulators, topologically non-trivial materials have attracted immense interest in the physics community in the past decade. One of the latest additions to the field, the material class of topological semimetals (TSMs), has grown at an extremely fast rate. While the prototype TSM, graphene, has been known for a while, the first 3D analogues of graphene have only been discovered recently. This Review, written from a chemistry perspective, intends to make the growing field of TSMs accessible to the wider community of materials scientists and scholars from related disciplines. To this end, we describe key features of TSMs, embedded in their electronic structure, and how they can be achieved based on chemical principles. We introduce the different classes of TSMs and review their salient representatives. Finally, selected properties and potential applications of these materials are discussed.