Bohmian quantum theory of motion for particles with position-dependent effective mass

We discuss the quantum dynamics of particles endowed with a position-depend ent effective mass within the de Broglie-Bohm causal interpretation of quan tum mechanics. The concomitant equations of motion are derived. The main ne w characteristic exhibited by these equations is that the non-constant mass gives rise to an additional term in the quantum potential and, consequentl y, to a Hamilton-Jacobi equation different from the one associated with the standard constant mass situation. Pie analyze, within the Bohmian approach , two particular aspects of the quantum mechanics of particles with non-con stant mass that have received special attention in recent literature: (i) t he connection rules at abrupt interfaces, and (ii) the form for the kinetic energy operator. We also provide a variational principle based on Fisher's information measure, which generalizes the one recently advanced by Regina tto for particles with constant mass, that leads to the equations of motion for R(r, t) and S(r, t) (Psi = R-1/2 exp(iS/h) being the wave function). ( C) 2001 Elsevier Science B.V. All rights reserved.