Статья
The Kohn–Luttinger superconductivity in idealized doped graphene
These notes have appeared as a result of a one-term course in superfluidity and superconductivity given by the author to fourth-year undergraduate students and first-year graduate students of the Department of Physics, Moscow State University of Education. The goal was not to give a detailed picture of these two macroscopic quantum phenomena with an extensive coverage of the experimental background and all the modern developments, but rather to show how the knowledge of undergraduate quantum mechanics and statistical physics could be used to discuss the basic concepts and simple problems, and draw parallels between superconductivity and superfluidity.
Superconductivity and superfluidity are two phenomena where quantum mechanics, typically constrained to the microscopic realm, shows itself on the macroscopic level. Conceptually and mathematically, these phenomena are related very closely, and some results obtained for one can, with a few modifications, be immediately carried over to the other. However, the student of these notes should be aware of important differences between superconductivity and superfluidity that stem mainly from two facts: (1) electrons in a superconductor carry a charge, therefore one has to take into account interaction with electromagnetic radiation; (2) electrons move in a lattice, therefore phonons play a role not only a mediators of attractive interaction between pairs of electrons, but also as scatterers of charge carriers.
Although these are notes on superfluidity and superconductivity, and there are a few cross-references, the two subjects can be studied independently with, perhaps, a little extra work by the student to fill in the gaps resulting from such study. The material of Chapter 1 introduces the method of second quantisation that is commonly used to discuss systems with many interacting particles. It is then applied in Chaper 2 to treat the uniform weakly interacting Bose gas within the approach by N. Bogoliubov, and in Chapter 4 to formulate the theory of the uniform superconducting state put forth by J. Bardeen, L. Cooper and R. Schrieffer. Chapter 3 presents the theory proposed independently by E. Gross and L. Pitaevskii of a non-uniform weakly interacting Bose gas, with a discussion of vortices, rotation of the condensate, and the Bogoliubov equations. In Chapter 5 we discuss the Ginzburd-Landau theory of a non-uniform superconductor near the critical temperature and apply it to a few simple problems such as the surface energy of the boundary between a normal metal and a superconductor, critical current and critical magnetic field, and vortices.
Graphene synthesis technology on substrates is promising, as is compatible with existing CMOS-technology. Knowledge about how to affect the substrate of choice for structural and electronic properties of graphene is important and opens up new opportunities in targeted influence on the properties of this unique material. Specialized measuring system was established to measure the galvanomagnetic characteristics of substrates multigraphene. Its structure and the measurement results are presented in the paper. For surface resistivity measurements we obtained samples were higher than that of natural graphite, but much lower than for samples of colloidal suspensions.
Рассчитан термодинамический потенциал сверхпроводящего квантового цилиндра. Изучена зависимость критической температуры и теплоемкости сверхпроводящей системы от концентрации электронов и радиуса нанотрубки.
Overview This book concisely presents the latest trends in the physics of superconductivity and superfluidity and magnetismin novel systems, as well as the problem of BCS-BEC crossover in ultracold quantum gases and high-Tc superconductors. It further illuminates the intensive exchange of ideas between these closely related fields of condensed matter physics over the last 30 years of their dynamic development. The content is based on the author’s original findings obtained at the Kapitza Institute, as well as advanced lecture courses he held at the Moscow Engineering Physical Institute, Amsterdam University, Loughborough University and LPTMS Orsay between 1994 and 2011. In addition to the findings of his group, the author discusses the most recent concepts in these fields, obtained both in Russia and in the West. The book consists of 16 chapters which are divided into four parts. The first part describes recent developments in superfluid hydrodynamics of quantum fluids and solids, including the fashionable subject of possible supersolidity in quantum crystals of 4He, while the second describes BCS-BEC crossover in quantum Fermi-Bose gases and mixtures, as well as in the underdoped states of cuprates. The third part is devoted to non-phonon mechanisms of superconductivity in unconventional (anomalous) superconductors, including some important aspects of the theory of high-Tc superconductivity. |The last part considers the anomalous normal state of novel superconductive materials and materials with colossal magnetoresistance (CMR). The book offers a valuable guide for senior-level undergraduate students and graduate students, postdoctoral and other researchers specializing in solid-state and low-temperature physics.
Пособие представляет собой лекции по вариационному исчислению. Предлагаемому курсу лекций соответствует сборник задач, который содержится в учебном пособии.
The conferences “Fundamental Problems of High Temperature Superconductivity” (FPS) have become traditional since the first one in 2004. The problem of high-temperature superconductivity remains highly topical: quite regularly, novel HTS materials come on stage (copper oxide high-Tc superconductors in 1986, magnesium diboride in 2001, iron pnictide and iron chalcogenide compounds in 2008, FeSe monolayers in 2012, and sulfur hydrides in 2014–2015). Achieving progressively higher superconducting transition temperatures remains an encouraging motivation for researchers in the field. Up to now, the highest Tc, 203 K, is achieved for H2S(H3S) pressurized at ∼ 2 Mbar. Nevertheless, a commonly accepted approach to the problem of high-temperature superconductivity is still missing.
Конференции ИТНТ-2018 проводится с целью предоставления возможности научных дискуссий и обсуждения результатов фундаментальных и прикладных исследований в области информационных технологий и нанотехнологий, привлечения молодежи в сферу передовых научных исследований, обмена опытом научнообразовательной деятельности при подготовке ИТНТ-специалистов. Тематика Конференции ИТНТ-2018 охватывает широкий круг областей применения информационных технологий в науке и высокотехнологичных отраслях промышленности. Основными направлениями работы Конференции ИТНТ-2018 являются: • Компьютерная оптика и нанофотоника о дифракционная оптика; о планарные оптические структуры; о оптические системы формирования изображений; о гиперспектральные изображающие системы; о нанофотоника; о волоконная оптика; • Обработка изображений и дистанционное зондирование Земли о обработка и анализ данных дистанционного зондирования Земли; о цифровая обработка изображений; о анализ движения; о реконструкция сцены о обработка и анализ данных дистанционного зондирования Земли; о защита мультимедиа и встраивание информации; о геоинформатика; • Математическое моделирование физико-технических процессов и систем о математическое моделирование информационных процессов; о математическое моделирование физических процессов и явлений; о математическое моделирование технических систем • Наука о данных о анализ данных; о машинное обучение; о безопасность, криптография; о высокопроизводительные вычисления. Одним из приоритетных направлений работы Конференции ИТНТ-2018 является образовательный аспект, заключающийся в предоставлении студентам и молодым ученым возможности ознакомиться с новейшими научными достижениями по тематике Конференции, а также с уникальным научным оборудованием и лабораторной базой Самарского университета, используемой для реализации современных научных проектов. В рамках Конференции проводится Молодежная школа, где молодые ученые и студенты получат возможность повысить свой профессиональный уровень и опубликовать свои научные результаты, в том числе в изданиях CEUR Workshop Proceedings (индексируется в Scopus) и Journal of Physics: Conference Series (индексируется в Web of Science).