Identical Particles and Second Quantization: Occupation Number Representation

2018 ◽  
Author(s):  
Norman J. Morgenstern Horing
Keyword(s):  
Occupation Number ◽  
Annihilation Operator ◽  
Pauli Exclusion Principle ◽  
Exclusion Principle ◽  
Number Representation ◽  
Second Quantization ◽  
Identical Particles ◽  
Fundamental Properties ◽  
Minimum Uncertainty ◽  
Creation Operators

Focusing on systems of many identical particles, Chapter 2 introduces appropriate operators to describe their properties in terms of Schwinger’s “measurement symbols.” The latter are then factorized into “creation” and “annihilation” operators, whose fundamental properties and commutation/anticommutation relations are derived in conjunction with the Pauli exclusion principle. This leads to “second quantization” with the Hamiltonian, number, linear and angular momentum operators expressed in terms of the annihilation and creation operators, as well as the occupation number representation. Finally, the concept of coherent states, as eigenstates of the annihilation operator, having minimum uncertainty, is introduced and discussed in detail.

scholarly journals Uma introdução à Teoria Quântica de muitas partículas aplicada a Física do Estado Sólido

1992 ◽  
Vol 14 (14) ◽  
pp. 35
Author(s):  
José Antônio Trindade Borges da Costa
Keyword(s):  
State Physics ◽  
Quantum Mechanics ◽  
Occupation Number ◽  
Particle Systems ◽  
Collective Excitations ◽  
Number Representation ◽  
Solid State Physics ◽  
General Representation ◽  
Second Quantization ◽  
The Many

Some fundamental concepts and mathematical tools of the quant um theory of many particle systems, which are indispensable to the study of solid state physics. are presented. The concepts of collective excitations and quasi-particles are stressed. Concerning the mathematical tools, Quantum Mechanics is presented in its general, representation independent formalism. The many-particle problem is approached in the occupation number representation, or second quantization. Finally, as an application the interaction between electrons and the vibrations of a crystal lattice, described in terms of elementary excitations of collective waves, i.e., phonons, is expressed and discussed within this framework.

scholarly journals A Deformed Quon Algebra

2019 ◽  
Vol 27 (2) ◽  
pp. 103-112 ◽  
Author(s):  
Hery Randriamaro
Keyword(s):  
Vector Space ◽  
Vacuum State ◽  
Pauli Exclusion Principle ◽  
Exclusion Principle ◽  
Dimensional Vector ◽  
Dimensional Vector Space ◽  
Infinite Dimensional ◽  
Bose Statistics ◽  
Particle Statistics ◽  
Creation Operators

AbstractThe quon algebra is an approach to particle statistics in order to provide a theory in which the Pauli exclusion principle and Bose statistics are violated by a small amount. The quons are particles whose annihilation and creation operators obey the quon algebra which interpolates between fermions and bosons. In this paper we generalize these models by introducing a deformation of the quon algebra generated by a collection of operators ai,k, (i, k) ∈ ℕ* × [m], on an infinite dimensional vector space satisfying the deformed q-mutator relations {a_j}_{,l}a_{i,k}^\dagger = qa_{i,k}^\dagger{a_{j,l}} + {q^{{\beta _{k,l}}}}{\delta _{i,j}} We prove the realizability of our model by showing that, for suitable values of q, the vector space generated by the particle states obtained by applying combinations of ai,k’s and a_{i,k}^\dagger ‘s to a vacuum state |0〉 is a Hilbert space. The proof particularly needs the investigation of the new statistic cinv and representations of the colored permutation group.

scholarly journals COMPLEX RATIONAL NUMBERS IN QUANTUM MECHANICS

2006 ◽  
Vol 20 (11n13) ◽  
pp. 1730-1741
Author(s):  
PAUL BENIOFF
Keyword(s):  
Quantum Mechanics ◽  
Occupation Number ◽  
Vacuum State ◽  
Rational Numbers ◽  
Integer Lattice ◽  
Binary Representation ◽  
Number Representation ◽  
Creation Operators

A binary representation of complex rational numbers and their arithmetic is described that is not based on qubits. It takes account of the fact that 0s in a qubit string do not contribute to the value of a number. They serve only as place holders. The representation is based on the distribution of four types of systems, corresponding to +1, -1, +i, -i, along an integer lattice. Complex rational numbers correspond to arbitrary products of four types of creation operators acting on the vacuum state. An occupation number representation is given for both bosons and fermions.

Hardness and HOMO-LUMO Gap Probed by the Helium Atom Pushing the Molecular Surface of the First-Row Hydride Molecules

2003 ◽  
Vol 68 (12) ◽  
pp. 2344-2354 ◽  
Author(s):  
Edyta Małolepsza ◽  
Lucjan Piela
Keyword(s):  
Helium Atom ◽  
Pauli Exclusion Principle ◽  
Structure Change ◽  
Molecular Surface ◽  
Exclusion Principle ◽  
Probe Position ◽  
Repulsion Energy ◽  
Ionic Dissociation ◽  
Probe Site ◽  
Homo Lumo

A molecular surface defined as an isosurface of the valence repulsion energy may be hard or soft with respect to probe penetration. As a probe, the helium atom has been chosen. In addition, the Pauli exclusion principle makes the electronic structure change when the probe pushes the molecule (at a fixed positions of its nuclei). This results in a HOMO-LUMO gap dependence on the probe site on the isosurface. A smaller gap at a given probe position reflects a larger reactivity of the site with respect to the ionic dissociation.

scholarly journals Testing the Pauli Exclusion Principle for Electrons at LNGS

2015 ◽  
Vol 61 ◽  
pp. 552-559 ◽  
Author(s):  
H. Shi ◽  
S. Bartalucci ◽  
S. Bertolucci ◽  
C. Berucci ◽  
A.M. Bragadireanu ◽  
...  
Keyword(s):  
Pauli Exclusion Principle ◽  
Exclusion Principle

Thermonuclear plasma conditions in stellar interiors

1981 ◽  
Vol 300 (1456) ◽  
pp. 641-648
Keyword(s):  
Nuclear Reactions ◽  
Pauli Exclusion Principle ◽  
Significant Rise ◽  
Exclusion Principle ◽  
Reaction Products ◽  
Thermonuclear Reactions ◽  
Radiated Energy ◽  
Large Numbers ◽  
Stellar Interiors ◽  
Late Stages

Thermonuclear reactions provide the main source of radiated energy for stars and they are also believed to be responsible for the production of most of the heavy elements in the Universe. The thermonuclear plasma is confined by the force of gravitation and for most of a star’s history the reactions occur slowly and steadily. In some circumstances, the properties of a star change very rapidly and explosive nuclear reactions occur. In very dense stellar interiors the energy states available to electrons may be limited by the Pauli exclusion principle. When thermonuclear reactions start in such a degenerate gas, a rise in temperature is not accompanied by a significant rise in pressure and as a result there may be a runaway increase in reaction rate. In contrast, when reactions start in a non-degenerate gas, there is normally an effective thermostat. A star is usually opaque to reaction products, so that there is no problem in maintaining the reaction temperature, but at late stages of stellar evolution nuclear or elementary particle reactions may produce large numbers of neutrinos and antineutrinos that do escape.

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