Effective Hamiltonian and Berry phase in a quantum mechanical system with time dependent boundary conditions

1991 ◽  
Vol 156 (1-2) ◽  
pp. 12-16 ◽  
Author(s):  
P. Pereshogin ◽  
P. Pronin
2018 ◽  
Vol 4 (1) ◽  
pp. 47-55
Author(s):  
Timothy Brian Huber

The harmonic oscillator is a quantum mechanical system that represents one of the most basic potentials. In order to understand the behavior of a particle within this system, the time-independent Schrödinger equation was solved; in other words, its eigenfunctions and eigenvalues were found. The first goal of this study was to construct a family of single parameter potentials and corresponding eigenfunctions with a spectrum similar to that of the harmonic oscillator. This task was achieved by means of supersymmetric quantum mechanics, which utilizes an intertwining operator that relates a known Hamiltonian with another whose potential is to be built. Secondly, a generalization of the technique was used to work with the time-dependent Schrödinger equation to construct new potentials and corresponding solutions.


2012 ◽  
Vol 90 (2) ◽  
pp. 187-191 ◽  
Author(s):  
R. MacKenzie ◽  
M. Pineault ◽  
L. Renaud-Desjardins

A condition on the Hamiltonian of an isospectral time-dependent quantum mechanical system is derived, which, if satisfied, implies optimal adiabaticity (defined later). The condition is expressed in terms of the Hamiltonian and the evolution operator related to it. Because the latter depends in a complicated way on the Hamiltonian, it is not yet clear how the condition can be used to extract useful information about the optimal Hamiltonian analytically. The condition is tested on an exactly-soluble time-dependent problem (a spin in a magnetic field), where perfectly adiabatic evolution can be easily identified.


1997 ◽  
Vol 52 (1-2) ◽  
pp. 63-65 ◽  
Author(s):  
Louis J. Boya

AbstractThe states of a quantum mechanical system are represented by rays in Hilbert space, but interference phenomena, Berry phase, etc. make reference to vectors. We show how to solve this apparent paradox by appropriate use of the vector bundle structure of quantum theory.


1988 ◽  
Vol 53 (8) ◽  
pp. 1607-1612 ◽  
Author(s):  
Štěpán Pick

The connection between moments of the electronic Hamiltonian and topology of a quantum mechanical system is studied. Based on simplifications similar to those usually employed in simple chemical and physical theories, criteria resembling the Hückel rule for cyclic conjugated systems are suggested. Several examples of interest in chemistry and solid physics are discussed. No information on the wave function is necessary in the present approach.


2003 ◽  
Vol 558 (3-4) ◽  
pp. 229-237 ◽  
Author(s):  
N. Beisert ◽  
C. Kristjansen ◽  
J. Plefka ◽  
M. Staudacher

1978 ◽  
Vol 10 (4) ◽  
pp. 725-729 ◽  
Author(s):  
J. V. Corbett

Quantum mechanics is usually described in the terminology of probability theory even though the properties of the probability spaces associated with it are fundamentally different from the standard ones of probability theory. For example, Kolmogorov's axioms are not general enough to encompass the non-commutative situations that arise in quantum theory. There have been many attempts to generalise these axioms to meet the needs of quantum mechanics. The focus of these attempts has been the observation, first made by Birkhoff and von Neumann (1936), that the propositions associated with a quantum-mechanical system do not form a Boolean σ-algebra. There is almost universal agreement that the probability space associated with a quantum-mechanical system is given by the set of subspaces of a separable Hilbert space, but there is disagreement over the algebraic structure that this set represents. In the most popular model for the probability space of quantum mechanics the propositions are assumed to form an orthocomplemented lattice (Mackey (1963), Jauch (1968)). The fundamental concept here is that of a partial order, that is a binary relation that is reflexive and transitive but not symmetric. The partial order is interpreted as embodying the logical concept of implication in the set of propositions associated with the physical system. Although this model provides an acceptable mathematical expression of the probabilistic structure of quantum mechanics in that the subspaces of a separable Hilbert space give a representation of an ortho-complemented lattice, it has several deficiencies which will be discussed later.


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