13 March 2000
Ž.
Physics Letters A 267 2000 208–211
www.elsevier.nlrlocaterphysleta
Self-force on a point charge and linear source in the space of a
screw dislocation
Sergio Azevedo
a,)
, Fernando Moraes
b
´
a
Departamento de Fısica, UniÕersidade Estadual de Feira de Santana Km-03, BR116-Norte, 44031-460, Feira de Santana, BA, Brazil
´
b
Laboratorio de Fısica Teorica e Computacional, Departamento de Fısica, UniÕersidade Federal de Pernambuco, 50670-910,
´´´ ´
Recife, PE, Brazil
Received 1 September 1999; received in revised form 28 January 2000; accepted 31 January 2000
Communicated by L.J. Sham
Abstract
Using a description of defect in solids in terms of three-dimensional gravity, we determine the eletrostatic self-force
acting on a point teste charge and a linear source in the presence of a screw dislocation. q2000 Published by Elsevier
Science B.V. All rights reserved.
PACS: 61.72.Lk; 41.20.Cv; 41.20.-q
1. Introduction
The effect of defects on properties of solids is a
wx
very active field of research 1 . The fact that the
theory of defects in solids can be reformulated as a
version of three-dimensional gravity has been shown
wx
by Katanaev and Volovich 2 . This formulation
corresponds to looking at the continuous limit of a
cristaline solid in which the static defect configura-
tion is characterized by a nontrivial metric corre-
sponding to static space-time.
wx wx
In recent works, Linet 3 and Smith 4 , using
different approaches, have shown that a charged
point particle placed in a static space-time produced
by an infinite straight cosmic string, is subjected to a
)
Corresponding author.
Ž.
E-mail addresses: sazevedo@uefs.br S. Azevedo ,
Ž.
moraes@df.ufpe.br F. Moraes .
finite repulsive electric self-force. On the other hand,
wx wx
Bezerra et al. 5 and Souradeep and Sahni 6 calcu-
lated the self-forces on the electric and magnetic
linear sources in the space-time of a cosmic string.
The purpose of this Letter is to investigate how
the self-force phenomenon manifests in the case of a
point charge and of an electric linear source, i.e., we
study what happens either to a point charge or to a
charge distribution in a medium with a screw dislo-
wx
cation 7 . Screw dislocations are topological defects,
which might be important in the crystal growth
wx
process. Recently Tamura et al. 8 and Ihara et al.
wx
9 showed that screw dislocations can also be con-
sidered in graphite.
2. Self-force on a point charge
We consider a combined defect, the dispiration,
which includes both the screw dislocation and the
0375-9601r00r$ - see front matter q 2000 Published by Elsevier Science B.V. All rights reserved.
Ž.
PII: S0375-9601 00 00089-X