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Peierls Instability Before
Sir Rudolf Ernst Peierls, (; ; 5 June 1907 – 19 September 1995) was a German-born British physicist who played a major role in Tube Alloys, Britain's nuclear weapon programme, as well as the subsequent Manhattan Project, the combined Allied nuclear bomb programme. His obituary in ''Physics Today'' described him as "a major player in the drama of the eruption of nuclear physics into world affairs". Peierls studied physics at the University of Berlin, at the University of Munich under Arnold Sommerfeld, the University of Leipzig under Werner Heisenberg, and ETH Zurich under Wolfgang Pauli. After receiving his DPhil from Leipzig in 1929, he became an assistant to Pauli in Zurich. In 1932, he was awarded a Rockefeller Fellowship, which he used to study in Rome under Enrico Fermi, and then at the Cavendish Laboratory at the University of Cambridge under Ralph H. Fowler. Because of his Jewish background, he elected to not return home after Adolf Hitler's rise to power in 1933, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berlin
Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constituent states, Berlin is surrounded by the State of Brandenburg and contiguous with Potsdam, Brandenburg's capital. Berlin's urban area, which has a population of around 4.5 million, is the second most populous urban area in Germany after the Ruhr. The Berlin-Brandenburg capital region has around 6.2 million inhabitants and is Germany's third-largest metropolitan region after the Rhine-Ruhr and Rhine-Main regions. Berlin straddles the banks of the Spree, which flows into the Havel (a tributary of the Elbe) in the western borough of Spandau. Among the city's main topographical features are the many lakes in the western and southeastern boroughs formed by the Spree, Havel and Dahme, the largest of which is Lake Müggelsee. Due to its l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wolfgang Pauli
Wolfgang Ernst Pauli (; ; 25 April 1900 – 15 December 1958) was an Austrian theoretical physicist and one of the pioneers of quantum physics. In 1945, after having been nominated by Albert Einstein, Pauli received the Nobel Prize in Physics for his "decisive contribution through his discovery of a new law of Nature, the exclusion principle or Pauli principle". The discovery involved spin theory, which is the basis of a theory of the structure of matter. Early years Pauli was born in Vienna to a chemist, Wolfgang Joseph Pauli (''né'' Wolf Pascheles, 1869–1955), and his wife, Bertha Camilla Schütz; his sister was Hertha Pauli, a writer and actress. Pauli's middle name was given in honor of his godfather, physicist Ernst Mach. Pauli's paternal grandparents were from prominent families of Prague; his great-grandfather was the publisher Wolf Pascheles. Pauli's mother, Bertha Schütz, was raised in her mother's Roman Catholic religion; Pauli was raised as a Roman Catholic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peierls Stress
Peierls stress (also known as the lattice friction stress) is the force (first described by Rudolf Peierls and modified by Frank Nabarro) needed to move a dislocation within a plane of atoms in the unit cell. The magnitude varies periodically as the dislocation moves within the plane. Peierls stress depends on the size and width of a dislocation and the distance between planes. Because of this, Peierls stress decreases with increasing distance between atomic planes. Yet since the distance between planes increases with planar atomic density, slip of the dislocation is preferred on closely packed planes. Peierls–Nabarro stress proportionality :\tau_\mathrm \propto Ge^ Where: :W = \frac= the dislocation width :G = shear modulus :\nu = Poisson's ratio :b = slip distance or Burgers vector :d = interplanar spacing The Peierls stress and yield strength temperature sensitivity The Peierls stress also relates to the temperature sensitivity of the yield strength In materia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peierls Substitution
The Peierls substitution method, named after the original work by Rudolf Peierls is a widely employed approximation for describing tightly-bound electrons in the presence of a slowly varying magnetic vector potential. In the presence of an external magnetic vector potential \mathbf, the translation operators, which form the kinetic part of the Hamiltonian in the tight-binding framework, are simply :\mathbf_x = , m+1,n\rangle\langle m,n, e^, \quad \mathbf_y = , m,n+1\rangle\langle m,n, e^ and in the second quantization formulation :\mathbf_x = \boldsymbol^\dagger_\boldsymbol_e^, \quad \mathbf_y = \boldsymbol^\dagger_\boldsymbol_e^. The phases are defined as : \theta^x_ = \frac\int_m^ A_x(x,n)\textx, \quad \theta^y_ = \frac\int_n^ A_y(m,y) \texty. Properties #The number of flux quanta per plaquette \phi_ is related to the lattice curl of the phase factor, \begin \boldsymbol\times\theta_& = \Delta_x\theta^y_-\Delta_y\theta^x_ = \left(\theta^y_-\theta^y_-\theta^x_+\theta^x_\rig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peierls Bracket
In theoretical physics, the Peierls bracket is an equivalent description of the Poisson bracket. It can be defined directly from the action and does not require the canonical coordinates and their canonical momenta In quantum mechanics, the canonical commutation relation is the fundamental relation between canonical conjugate quantities (quantities which are related by definition such that one is the Fourier transform of another). For example, hat x,\hat p ... to be defined in advance. The bracket :[A,B/math> is defined as :D_A(B)-D_B(A), as the difference between some kind of action of one quantity on the other, minus the flipped term. In quantum mechanics, the Peierls bracket becomes a commutator i.e. a Lie bracket of vector fields, Lie bracket. References Peierls, R. "The Commutation Laws of Relativistic Field Theory," Proc. R. Soc. Lond. August 21, 1952 214 1117 143-157. Theoretical physics {{theoretical-physics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ising Model
The Ising model () (or Lenz-Ising model or Ising-Lenz model), named after the physicists Ernst Ising and Wilhelm Lenz, is a mathematical model of ferromagnetism in statistical mechanics. The model consists of discrete variables that represent magnetic dipole moments of atomic "spins" that can be in one of two states (+1 or −1). The spins are arranged in a graph, usually a lattice (where the local structure repeats periodically in all directions), allowing each spin to interact with its neighbors. Neighboring spins that agree have a lower energy than those that disagree; the system tends to the lowest energy but heat disturbs this tendency, thus creating the possibility of different structural phases. The model allows the identification of phase transitions as a simplified model of reality. The two-dimensional square-lattice Ising model is one of the simplest statistical models to show a phase transition. The Ising model was invented by the physicist , who gave it as a prob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noor Muhammad Butt
Noor Muhammad Butt (Urdu: نور محمد بٹ); b. 3 June 1936), , also known as "N. M. Butt", is a Pakistani nuclear physicist and professor of physics at the Preston University who is known for his research publications in understanding the gamma-rays burst, Mössbauer effect, diffraction, later the nanotechnology. Besides teaching courses in topics involving the modern physics, his career has spent working in branches of physics at the national laboratory in Nilore and has authored several college textbooks in physics based on his research, and presently serving as the chairman of the Institute of Nano Science and Technology at the Preston University. Biography Butt was born in Sialkot, Punjab, British India on 3 June 1936. He is of Kashmiri descent. He completed his matriculation from the Muslim High School, Sialkot. In 1951, Butt enrolled to attend the Murray College to study physics and graduated with BSc in physics in 1955, standing top in his class of 1955 of the Mu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stanley Mandelstam
Stanley Mandelstam (; 12 December 1928 – 23 June 2016) was a South African theoretical physicist. He introduced the relativistically invariant Mandelstam variables into particle physics in 1958 as a convenient coordinate system for formulating his double dispersion relations. The double dispersion relations were a central tool in the bootstrap program which sought to formulate a consistent theory of infinitely many particle types of increasing spin. Early life Mandelstam was born in Johannesburg, South Africa to a Jewish family.William D. Rubinstein, Michael Jolles, Hilary L. Rubinstein, ''The Palgrave Dictionary of Anglo-Jewish History'', Palgrave Macmillan (2011), p. 110 Work Mandelstam, along with Tullio Regge, did the initial development of the Regge theory of strong interaction phenomenology. He reinterpreted the analytic growth rate of the scattering amplitude as a function of the cosine of the scattering angle as the power law for the falloff of scattering amplitudes a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Stewart Bell
John Stewart Bell FRS (28 July 1928 – 1 October 1990) was a physicist from Northern Ireland and the originator of Bell's theorem, an important theorem in quantum physics regarding hidden-variable theories. In 2022, the Nobel Prize in Physics was awarded to Alain Aspect, John Clauser, and Anton Zeilinger for work on Bell inequalities and the experimental validation of Bell's theorem. Biography Early life and work Bell was born in Belfast, Northern Ireland. When he was 11 years old, he decided to be a scientist, and at 16 graduated from Belfast Technical High School. Bell then attended the Queen's University of Belfast, where, in 1948, he obtained a bachelor's degree in experimental physics and, a year later, a bachelor's degree in mathematical physics. He went on to complete a Ph.D. in physics at the University of Birmingham in 1956, specialising in nuclear physics and quantum field theory. In 1954, he married Mary Ross, also a physicist, whom he had met while working ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James S
James is a common English language surname and given name: *James (name), the typically masculine first name James * James (surname), various people with the last name James James or James City may also refer to: People * King James (other), various kings named James * Saint James (other) * James (musician) * James, brother of Jesus Places Canada * James Bay, a large body of water * James, Ontario United Kingdom * James College, a college of the University of York United States * James, Georgia, an unincorporated community * James, Iowa, an unincorporated community * James City, North Carolina * James City County, Virginia ** James City (Virginia Company) ** James City Shire * James City, Pennsylvania * St. James City, Florida Arts, entertainment, and media * ''James'' (2005 film), a Bollywood film * ''James'' (2008 film), an Irish short film * ''James'' (2022 film), an Indian Kannada-language film * James the Red Engine, a character in ''Thomas the Tank En ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walter Marshall, Baron Marshall Of Goring
Walter Charles Marshall, Baron Marshall of Goring (5 March 1932 in Rumney, Cardiff – 20 February 1996, in London) was a noted theoretical physicist and leader in the UK's energy sector. Early life The son of Frank Marshall and Amy Pearson, he attended the grammar school St Illtyd's Boys College (now St Illtyd's Catholic High School). He studied mathematical physics at Birmingham University and gained a PhD there under Rudolf Peierls. Career He joined the Theoretical Physics Division at AERE Harwell in 1954, succeeding Brian Flowers as Head of that Division in 1960 and becoming Director of AERE in 1968; he eventually was appointed Chairman of the United Kingdom Atomic Energy Authority in 1981. CEGB As a champion of nuclear power, he was appointed, in 1983, to be chairman of the Central Electricity Generating Board. He was also highly sceptical of fusion power, famously noting that "fusion is an idea with infinite possibility and zero chance of success." In 1989, with th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stuart Thomas Butler
Stuart Thomas Butler (4 July 1926 – 15 May 1982) was an Australian nuclear physicist who served as Director of the Australian Atomic Energy Commission from 1977 until 1982, and was noted for his contributions to theoretical physics including stripping reactions, energy loss of particles in plasma and atmospheric tides induced by absorption of solar radiation in the ozone layer. Butler was born in Naracoorte in South Australia; he was the eldest of three sons born to his Welsh school teacher father and Australian mother. He attended Murray Bridge and Gumeracha primary schools and Birdwood High School where he showed aptitude in mathematics, science, English and music. When he completed high school he considered studying piano at the Conservatorium of Music, but he received a scholarship to do his undergraduate studies at the University of Adelaide, here he was greatly influenced by physicist Kerr Grant and mathematician Hans Schwerdtfeger.Watson-Munro, CN. 1983Stuart Thomas But ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
