Problem of the Complete Measurement for CP-violating Parameters in Neutral B-meson Decays

Phenomenological CP-violating parameters in decays of neutral B-mesons are discussed. Special attention is given to the degree of their measurability. We emphasize important role of the sign of $\Delta m_B$ and suggest how it could be determined experimentally.Comment: 12 pages, no figures; some small errors are corrected, publication reference is appende

ТУРИЗМ НА РЕАКТИВНОЙ ТЯГЕ

Describing the post-war period from 1946 onwards, the author analyzes in parallel the trends in the development of international tourism in the country and vehicles, infrastructure, accompanying intensification and acceleration of tourist exchange. The author highlights starting points associated with revolutionary changes in civil aircraft construction, manufacturing of locomotive equipment, rolling stock on railways, the emergence of more comfortable and high-speed vessels and vehicles. For large domestic areas combination of the factors described in the article had an undeniable value, and generalization made in the course of review is natural and fair: transport has been and remains the support of tourism.Характеризуя послевоенный период начиная с 1946 года, автор анализирует параллельно тенденции развития международного туризма в стране и транспортных средств, инфраструктуры, сопутствующих интенсификации и ускорению процессов туристического обмена. Особо отмечены отправные моменты, связанные с революционными изменениями в гражданском самолетостроении, производстве локомотивной техники, подвижного состава на железных дорогах, появление более комфортабельных и скоростных судов и автомашин. Для огромных отечественных территорий сочетание названных в статье факторов имело неоспоримое значение, и сделанные по ходу обзора обобщения закономерны и справедливы: транспорт был и остается опорой туризма

БАМ и развитие туризма в Восточной Сибири

[For the English abstract and full text of the article please see the attached PDF-File (English version follows Russian version)].ABSTRACT The richest natural reserves that the Siberian and Far Eastern regions have along the Baikal-Amur Mainline (called in short in conformity with Russian practices as BAM) make this zone more attractive for tourists and people ready to go here for balneological resorts, mineral waters, all kinds of mountain, water and any other trips and excursions. Opportunities of the region are assessed in the article, proceeding from the really existing prerequisites for development and outlined prospects for individual territories, projects and spheres of activity. Keywords: Baikal-Amur Mainline, Eastern Siberia, Far East, tourism, economy, development of new territories, transport complex, development potential.Текст аннотации на англ. языке и полный текст статьи на англ. языке находится в прилагаемом файле ПДФ (англ. версия следует после русской версии).Богатейшие природные запасы, которыми располагают сибирские и дальневосточные районы вдоль Байкало-Амурской магистрали, делают эту зону всё более привлекательной для туристов и людей, готовых ехать сюда на бальнеологические курорты, минеральные воды, а также виды горных, водных и любых других путешествий и экскурсий. Возможности региона оцениваются в статье, исходя из реально существующих предпосылок развития и намечаемых перспектив для отдельных территорий, проектов и сфер деятельности

Медленно строим, чтобы быстро ехать

For the English full text of the article please see the attached PDF-File (English version follows Russian version).ABSTRACT Nowadays, in countries with developed high-speed passenger transport, the most noticeable growth rates in tourism are observed, namely, high speeds attract many travel enthusiasts, increase passenger and tourist traffic, ensuring the lowest total travel time with the most decent safety, comfort and economy. The era of fast trains, however, is not so long as to acquire a full-fledged history. But nonetheless the HSR already has the past. And it makes to show itself. Railway tour routes, varied in geographical location, form and content, help to do that. Keywords: railway, high-speed rail, history, international lines, passenger flow, tourism development.Полный текст на англ. языке находится в прилагаемом файле ПДФ (англ. версия следует после русской версии).Сегодня в странах с развитым высокоскоростным пассажирским транспортом отмечаются и самые заметные темпы роста туризма, именно высокие скорости привлекают многих любителей путешествий, дают увеличение объёма перевозок пассажиров и туристов, обеспечивая наименьшее суммарное время в пути следования при самых достойных показателях безопасности, комфортабельности и экономичности. Эпоха быстрых поездов, впрочем, не столь долгая, чтобы обзавестись полновесной историей. Но прошлое у ВСМ уже, тем не менее, есть. И оно заставляет о себе напоминать. Чему помогают разнообразные по географическому расположению, форме и содержанию маршруты железнодорожных туров

Topological Graphene plasmons in a plasmonic realization of the Su-Schrieffer-Heeger Model

Graphene hybrids, made of thin insulators, graphene, and metals can support propagating acoustic plasmons (AGPs). The metal screening modifies the dispersion relation of usual graphene plasmons leading to slowly propagating plasmons, with record confinement of electromagnetic radiation. Here, we show that a graphene monolayer, covered by a thin dielectric material and an array of metallic nanorods, can be used as a robust platform to emulate the Su-Schrieffer-Heeger model. We calculate the Zak's phase of the different plasmonic bands to characterize their topology. The system shows bulk-edge correspondence: strongly localized interface states are generated in the domain walls separating arrays in different topological phases. We find signatures of the nontrivial phase which can directly be probed by far-field mid-IR radiation, hence allowing a direct experimental confirmation of graphene topological plasmons. The robust field enhancement, highly localized nature of the interface states, and their gate-tuned frequencies expand the capabilities of AGP-based devices.T.G.R. acknowledges funding from Fundacao para a Ciência e a Tecnologia and Instituto de Telecomunicacoes. grant number UID/50008/2020.in the framework of the project Sym-Break and Mario G. Silveirinha for useful discussions. Y.V.B., N.M.R.P. and F.H.L.K. acknowledge support from the European Commission through the project "Graphene-Driven Revolutions in ICT and Beyond" (ref. no. 881603, CORE 3). Y.V.B. and N.M.R.P. acknowledge COMPETE 2020, PORTUGAL 2020, FEDER, and the Portuguese Foundation for Science and Technology (FCT) through project POCI-010145-FEDER-028114. F.H.L.K. acknowledges financial support from the Government of Catalonia through the SGR grant, the Spanish Ministry of Economy and Competitiveness, through the "Severo Ochoa" Programme for Centres of Excellence in RD (SEV-2015-0522), Fundacio Cellex Barcelona, Generalitat de Catalunya through the CERCA program, the Mineco grants Ramon y Cajal (RYC-201212281), Plan Nacional (FIS2013-47161-P and FIS2014-59639JIN), and the Agency for Management of University and Research Grants (AGAUR) 2017 SGR 1656. This work was supported by the ERC TOPONANOP under grant agreement n 726001 and the MINECO Plan Nacional Grant 2DNANOTOP under reference no FIS2016-81044-P

Topological photonic Tamm states and the Su-Schrieffer-Heeger model

In this paper we study the formation of topological Tamm states at the interface between a semi-infinite one-dimensional (1D) photonic crystal and a metal. We show that when the system is topologically nontrivial there is a single Tamm state in each of the band gaps, whereas if it is topologically trivial the band gaps host no Tamm states. We connect the disappearance of the Tamm states with a topological transition from a topologically nontrivial system to a topologically trivial one. This topological transition is driven by the modification of the dielectric functions in the unit cell. Our interpretation is further supported by an exact mapping between the solutions of Maxwell's equations and the existence of a tight-binding representation of those solutions. We show that the tight-binding representation of the 1D photonic crystal, based on Maxwell's equations, corresponds to a Su-Schrieffer-Heeger-type model (SSH model) for each set of pairs of bands. By expanding this representation near the band edge we show that the system can be described by a Dirac-like Hamiltonian. It allows one to characterize the topology associated with the solution of Maxwell's equations via the winding number. In addition, for the infinite system, we provide an analytical expression for the photonic bands from which the band gaps can be computed.N.M.R.P., M.I.V., and Y.V.B. acknowledge support from the European Commission through the project GrapheneDriven Revolutions in ICT and Beyond (Ref. No. 785219) and the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Financing UID/FIS/04650/2019. N.M.R.P., T.G.R., and Y.V.B. acknowledge COMPETE2020, PORTUGAL2020, FEDER, and the Portuguese Foundation for Science and Technology (FCT) through Project No. POCI-01-0145-FEDER-028114. The authors acknowledge Andre Chaves for suggesting the starting point of the analytical approach to the photonic bands. N.M.R.P. acknowledges stimulating discussions with Joaquin Fernandez-Rossier on the topic of the paper. J.C.G.H. acknowledges the hospitality of the physics department of SDU, Denmark, where this work was completed. The authors are thankful to Asger Mortensen and Mario Silveirinha for their careful and critical reading of the manuscript

KITE : high-performance accurate modelling of electronic structure and response functions of large molecules, disordered crystals and heterostructures

We present KITE, a general purpose open-source tight-binding software for accurate real-space simulations of electronic structure and quantum transport properties of large-scale molecular and condensed systems with tens of billions of atomic orbitals (N ∼ 10^10). KITE’s core is written in C++, with a versatile Python-based interface, and is fully optimized for shared memory multi-node CPU architectures, thus scalable, efficient and fast. At the core of KITE is a seamless spectral expansion of lattice Green’s functions, which enables large-scale calculations of generic target functions with uniform convergence and fine control over energy resolution. Several functionalities are demonstrated, ranging from simulations of local density of states and photo-emission spectroscopy of disordered materials to large-scale computations of optical conductivity tensors and real-space wave-packet propagation in the presence of magneto-static fields and spin–orbit coupling. On-the-fly calculations of real-space Green’s functions are carried out with an efficient domain decomposition technique, allowing KITE to achieve nearly ideal linear scaling in its multi-threading performance. Crystalline defects and disorder, including vacancies, adsorbates and charged impurity centres, can be easily set up with KITE’s intuitive interface, paving the way to user-friendly large-scale quantum simulations of equilibrium and non-equilibrium properties of molecules, disordered crystals and heterostructures subject to a variety of perturbations and external conditions

Magnetic effects in sulfur-decorated graphene

The interaction between two different materials can present novel phenomena that are quite different from the physical properties observed when each material stands alone. Strong electronic correlations, such as magnetism and superconductivity, can be produced as the result of enhanced Coulomb interactions between electrons. Two-dimensional materials are powerful candidates to search for the novel phenomena because of the easiness of arranging them and modifying their properties accordingly. In this work, we report magnetic effects of graphene, a prototypical non-magnetic two-dimensional semi-metal, in the proximity with sulfur, a diamagnetic insulator. In contrast to the well-defined metallic behaviour of clean graphene, an energy gap develops at the Fermi energy for the graphene/sulfur compound with decreasing temperature. This is accompanied by a steep increase of the resistance, a sign change of the slope in the magneto-resistance between high and low fields, and magnetic hysteresis. A possible origin of the observed electronic and magnetic responses is discussed in terms of the onset of low-temperature magnetic ordering. These results provide intriguing insights on the search for novel quantum phases in graphene-based compounds.Comment: 6 pages and 5 figure

Entanglement in the One-dimensional Kondo Necklace Model

We discuss the thermal and magnetic entanglement in the one-dimensional Kondo necklace model. Firstly, we show how the entanglement naturally present at zero temperature is distributed among pairs of spins according to the strength of the two couplings of the chain, namely, the Kondo exchange interaction and the hopping energy. The effect of the temperature and the presence of an external magnetic field is then investigated, being discussed the adjustment of these variables in order to control the entanglement available in the system. In particular, it is indicated the existence of a critical magnetic field above which the entanglement undergoes a sharp variation, leading the ground state to a completely unentangled phase.Comment: 8 pages, 13 EPS figures. v2: four references adde