Issue
EPL
Volume 80, Number 3, November 2007
Article Number 30004
Number of page(s) 5
Section General
DOI http://dx.doi.org/10.1209/0295-5075/80/30004
Published online 10 October 2007
EPL, 80 (2007) 30004
DOI: 10.1209/0295-5075/80/30004

Can degenerate bound states occur in one-dimensional quantum mechanics?

Sayan Kar1 and Rajesh R. Parwani2

1  Department of Physics and Centre for Theoretical Studies, Indian Institute of Technology - Kharagpur 721 302, WB, India
2  Department of Physics and University Scholars Programme, National University of Singapore - Kent Ridge, Singapore

sayan@cts.iitkgp.ernet.in
parwani@nus.edu.sg

received 13 July 2007; accepted in final form 13 September 2007; published November 2007
published online 10 October 2007

Abstract
We point out that bound states, degenerate in energy but differing in parity, may form in one-dimensional quantum systems even if the potential is non-singular in any finite domain. Such potentials are necessarily unbounded from below at infinity and occur in several different contexts, such as in the study of localised states in brane-world scenarios. We describe how to construct large classes of such potentials and give explicit analytic expressions for the degenerate bound states. Some of these bound states occur above the potential maximum while some are below. Various unusual features of the bound states are described and after highlighting those that are ansatz independent, we suggest that it might be possible to observe such parity-paired degenerate bound states in specific mesoscopic systems.

PACS
03.65.-w - Quantum mechanics.
03.65.Ge - Solutions of wave equations: bound states.

© Europhysics Letters Association 2007