Electromagnetic field configurations ensuring charge screening and confinement in two-dimensional massless electrodynamics

Electromagnetic fields in which the determinant of the Dirac operator of a fermion system in an external field D(A) vanishes are responsible for charge screening and quantum-number confinement in two-dimensional electrodynamics (QED/sub 2/) with massless electrons (quarks). Two classes of fields (A and B) leading to D(A) = 0 are important. In QED/sub 2/ fields of class A generate a screening mechanism based on the compulsory production of compensating charges in such fields. The concept of change of the two-dimensional topological charge can be introduced for fields of class B. Fields of class B (a) lead to the formation of a chiral condensate in the QED/sub 2/ vacuum, (b) determine the properties of states of the model, ensuring (in spite of the presence of the condensate) helicity conservation of the physical states, and (c) are responsible for the soft nature of the transition of the quarks of the model into hadrons in the separation of a quark pair (''e/sup +/ e/sup -/ annihilation'' in QED/sub 2/).