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Lev Shubnikov
Lev Vasilyevich Shubnikov (russian: Лев Васи́льевич Шу́бников; uk, Лев Васильович Шубников) (September 29, 1901 – November 10, 1937) was a Soviet experimental physicist who worked in the Netherlands and USSR. In 1937 he was executed during the Ukrainian Physics and Technology Institute Affair on the basis of falsified charges as part of the Great Purge. Early life Shubnikov was born into the family of a Saint Petersburg accountant. After graduating from a gymnasium he entered Leningrad University. This was the first year of the Russian Civil War and he was the only student of that year attending the physics department. While yachting in the Gulf of Finland in 1921, he accidentally sailed from Saint Petersburg to Finland, was sent to Germany and could not return to Russia until 1922. He then continued his education in the Leningrad Polytechnical Institute, graduating in 1926. During his university training he worked with Ivan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lev Shubnikov
Lev Vasilyevich Shubnikov (russian: Лев Васи́льевич Шу́бников; uk, Лев Васильович Шубников) (September 29, 1901 – November 10, 1937) was a Soviet experimental physicist who worked in the Netherlands and USSR. In 1937 he was executed during the Ukrainian Physics and Technology Institute Affair on the basis of falsified charges as part of the Great Purge. Early life Shubnikov was born into the family of a Saint Petersburg accountant. After graduating from a gymnasium he entered Leningrad University. This was the first year of the Russian Civil War and he was the only student of that year attending the physics department. While yachting in the Gulf of Finland in 1921, he accidentally sailed from Saint Petersburg to Finland, was sent to Germany and could not return to Russia until 1922. He then continued his education in the Leningrad Polytechnical Institute, graduating in 1926. During his university training he worked with Ivan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leiden
Leiden (; in English and archaic Dutch also Leyden) is a city and municipality in the province of South Holland, Netherlands. The municipality of Leiden has a population of 119,713, but the city forms one densely connected agglomeration with its suburbs Oegstgeest, Leiderdorp, Voorschoten and Zoeterwoude with 206,647 inhabitants. The Netherlands Central Bureau of Statistics (CBS) further includes Katwijk in the agglomeration which makes the total population of the Leiden urban agglomeration 270,879, and in the larger Leiden urban area also Teylingen, Noordwijk, and Noordwijkerhout are included with in total 348,868 inhabitants. Leiden is located on the Oude Rijn, at a distance of some from The Hague to its south and some from Amsterdam to its north. The recreational area of the Kaag Lakes (Kagerplassen) lies just to the northeast of Leiden. A university city since 1575, Leiden has been one of Europe's most prominent scientific centres for more than four centuries. Leide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paramagnetism
Paramagnetism is a form of magnetism whereby some materials are weakly attracted by an externally applied magnetic field, and form internal, induced magnetic fields in the direction of the applied magnetic field. In contrast with this behavior, diamagnetic materials are repelled by magnetic fields and form induced magnetic fields in the direction opposite to that of the applied magnetic field. Paramagnetic materials include most chemical elements and some compounds; they have a relative magnetic permeability slightly greater than 1 (i.e., a small positive magnetic susceptibility) and hence are attracted to magnetic fields. The magnetic moment induced by the applied field is linear in the field strength and rather weak. It typically requires a sensitive analytical balance to detect the effect and modern measurements on paramagnetic materials are often conducted with a SQUID magnetometer. Paramagnetism is due to the presence of unpaired electrons in the material, so most atoms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antiferromagnetism
In materials that exhibit antiferromagnetism, the magnetic moments of atoms or molecules, usually related to the spins of electrons, align in a regular pattern with neighboring spins (on different sublattices) pointing in opposite directions. This is, like ferromagnetism and ferrimagnetism, a manifestation of ordered magnetism. The phenomenon of antiferromagnetism was first introduced by Lev Landau in 1933. Generally, antiferromagnetic order may exist at sufficiently low temperatures, but vanishes at and above the Néel temperature – named after Louis Néel, who had first identified this type of magnetic ordering. Above the Néel temperature, the material is typically paramagnetic. Measurement When no external field is applied, the antiferromagnetic structure corresponds to a vanishing total magnetization. In an external magnetic field, a kind of ferrimagnetic behavior may be displayed in the antiferromagnetic phase, with the absolute value of one of the sublattice magneti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type-II Superconductor
In superconductivity, a type-II superconductor is a superconductor that exhibits an intermediate phase of mixed ordinary and superconducting properties at intermediate temperature and fields above the superconducting phases. It also features the formation of magnetic field vortices with an applied external magnetic field. This occurs above a certain critical field strength ''Hc1''. The vortex density increases with increasing field strength. At a higher critical field ''Hc2'', superconductivity is destroyed. Type-II superconductors do not exhibit a complete Meissner effect. History In 1935, Rjabinin and Shubnikov experimentally discovered the Type-II superconductors. In 1950, the theory of the two types of superconductors was further developed by Lev Landau and Vitaly Ginzburg in their paper on Ginzburg–Landau theory. In their argument, a type-I superconductor had positive free energy of the superconductor-normal metal boundary. Ginzburg and Landau pointed out the possibilit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ivan V
Ivan V Alekseyevich (russian: Иван V Алексеевич; – ) was Tsar of Russia between 1682 and 1696, jointly ruling with his younger half-brother Peter I. Ivan was the youngest son of Alexis I of Russia by his first wife, Maria Miloslavskaya, while Peter was the only son of Alexis by his second wife, Natalya Naryshkina. Ivan's reign was solely titular because he had serious physical and mental issues. Early life and accession Ivan V was born in 1666 in Moscow, the youngest son of Tsar Alexis and Maria Miloslavskaya. Only two of his older brothers survived childhood; his eldest brother, Alexei, died aged 15 in 1670, therefore his second brother, Feodor, became tsar upon the death of their father. When Feodor died in 1682 without leaving an heir, Ivan, who was thought to be "infirm in body and mind", was passed over in favor of his younger half-brother, Peter. The church and the Naryshkins (family of Peter's mother, Natalya Naryshkina) supported Peter's ascension ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ukraine
Ukraine ( uk, Україна, Ukraïna, ) is a country in Eastern Europe. It is the second-largest European country after Russia, which it borders to the east and northeast. Ukraine covers approximately . Prior to the ongoing Russian invasion, it was the eighth-most populous country in Europe, with a population of around 41 million people. It is also bordered by Belarus to the north; by Poland, Slovakia, and Hungary to the west; and by Romania and Moldova to the southwest; with a coastline along the Black Sea and the Sea of Azov to the south and southeast. Kyiv is the nation's capital and largest city. Ukraine's state language is Ukrainian; Russian is also widely spoken, especially in the east and south. During the Middle Ages, Ukraine was the site of early Slavic expansion and the area later became a key centre of East Slavic culture under the state of Kievan Rus', which emerged in the 9th century. The state eventually disintegrated into rival regional po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kharkiv
Kharkiv ( uk, wikt:Харків, Ха́рків, ), also known as Kharkov (russian: Харькoв, ), is the second-largest List of cities in Ukraine, city and List of hromadas of Ukraine, municipality in Ukraine.Kharkiv "never had eastern-western conflicts" ''Euronews'' (23 October 2014) Located in the northeast of the country, it is the largest city of the historic Sloboda Ukraine, Slobozhanshchyna region. Kharkiv is the administrative centre of Kharkiv Oblast and of the surrounding Kharkiv Raion. The latest population is Kharkiv was founded in 1654 as Kharkiv fortress, and after these humble beginnings, it grew to be a major centre of industry, trade and Ukrainian culture in the Russian Empire. At the beginning of the 20th century, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kharkiv Institute Of Physics And Technology
The National Science Center Kharkiv Institute of Physics and Technology (KIPT) ( uk, Національний науковий центр «Харківський фізико-технічний інститут»), formerly the Ukrainian Physics and Technology Institute (UPTI) is the oldest and largest physical science research centre in Ukraine. Today it is known as a science center as it consists of several institutes that are part of the Kharkiv Institute of Physics and Technology science complex. History The institute was founded on 30 October 1928, by the Government of Soviet UkraineTaravarov, Ya. Landau in a field of negative values (Ландау в области отрицательных значений)'. Vokrug Sveta. 15 December 2008. on an initiative of Abram Ioffe on the northern outskirts of Kharkiv (in khutir Piatykhatky) as the Ukrainian Institute of Physics and Technology for the purpose of research on nuclear physics and condensed matter physics. From the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shubnikov–de Haas Effect
An oscillation in the conductivity of a material that occurs at low temperatures in the presence of very intense magnetic fields, the Shubnikov–de Haas effect (SdH) is a macroscopic manifestation of the inherent quantum mechanical nature of matter. It is often used to determine the effective mass of charge carriers (electrons and electron holes), allowing investigators to distinguish among majority and minority carrier populations. The effect is named after Wander Johannes de Haas and Lev Shubnikov. Physical process At sufficiently low temperatures and high magnetic fields, the free electrons in the conduction band of a metal, semimetal, or narrow band gap semiconductor will behave like simple harmonic oscillators. When the magnetic field strength is changed, the oscillation period of the simple harmonic oscillators changes proportionally. The resulting energy spectrum is made up of Landau levels separated by the cyclotron energy. These Landau levels are further split by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Field
A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to the magnetic field. A permanent magnet's magnetic field pulls on ferromagnetic materials such as iron, and attracts or repels other magnets. In addition, a nonuniform magnetic field exerts minuscule forces on "nonmagnetic" materials by three other magnetic effects: paramagnetism, diamagnetism, and antiferromagnetism, although these forces are usually so small they can only be detected by laboratory equipment. Magnetic fields surround magnetized materials, and are created by electric currents such as those used in electromagnets, and by electric fields varying in time. Since both strength and direction of a magnetic field may vary with location, it is described mathematically by a function assigning a vector to each point of space, cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetoresistance
Magnetoresistance is the tendency of a material (often ferromagnetic) to change the value of its electrical resistance in an externally-applied magnetic field. There are a variety of effects that can be called magnetoresistance. Some occur in bulk non-magnetic metals and semiconductors, such as geometrical magnetoresistance, Shubnikov–de Haas oscillations, or the common positive magnetoresistance in metals. Other effects occur in magnetic metals, such as negative magnetoresistance in ferromagnets or anisotropic magnetoresistance (AMR). Finally, in multicomponent or multilayer systems (e.g. magnetic tunnel junctions), giant magnetoresistance (GMR), tunnel magnetoresistance (TMR), colossal magnetoresistance (CMR), and extraordinary magnetoresistance (EMR) can be observed. The first magnetoresistive effect was discovered in 1856 by William Thomson, better known as Lord Kelvin, but he was unable to lower the electrical resistance of anything by more than 5%. Today, systems includi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
