PERSISTENT CURRENTS AND MAGNETIZATION IN 2-DIMENSIONAL MAGNETIC QUANTUM-SYSTEMS

Persistent currents and magnetization are considered for a two-dimensi onal electron (or gas of electrons) coupled to various magnetic fields . Thermodynamic formulae for the magnetization and the persistent curr ent are established and the ''classical'' relationship between current and magnetization is shown to hold for systems invariant both by tran slation and rotation. Applications are given, including the point vort ex superposed onto an homogeneous magnetic field, the quantum Hall geo metry (an electric field and an homogeneous magnetic field) and the ra ndom magnetic impurity problem (a random distribution of point vortice s). (C) 1998 Elsevier Science B.V.