Connection between conserved quantities and degeneracies in quantum systems

Citation data:

American Journal of Physics, ISSN: 0002-9505, Vol: 63, Issue: 11, Page: 1017-1020

Publication Year:
1995
Usage 120
Downloads 82
Abstract Views 38
Captures 4
Readers 4
Repository URL:
https://works.bepress.com/evangelos_hadjimichael/2; https://digitalcommons.fairfield.edu/engineering-facultypubs/2
DOI:
10.1119/1.18048
Author(s):
Fallieros, S.; Hadjimichael, Evangelos
Publisher(s):
American Association of Physics Teachers (AAPT)
Tags:
Engineering
article description
In the framework of quantum theory, we present one theorem and three corollaries regarding the direct connection between constants of motion of a physical system and degeneracies of its energy eigenvalues. It is shown that this connection emerges when there exist quantum operators which commute with the Hamiltonian, but not with each other. Further it is shown that if the commutator of these operators is a nonvanishing constant number then (a) all the eigenvalues of the system are degenerate, and (b) the degree of degeneracy is infinite. A number of examples are discussed including the parity degeneracy of the hydrogen atom and the infinite degeneracy of the Landau levels of a charged particle in a constant magnetic field. (C) 1995 American Association of Physics Teachers.