Stress field in quantum systems

Abstract

Microscopic stress tensors for the general interacting quantum system are obtained which consist of a configuration-dependent term and a momentum-flux-density term. The arbitrariness that exists in the momentum-flux contribution to the total stress is quantum-mechanical in origin, and reduces to the choice of one constant. Short-ranged configurational stresses are derived which give Maxwell's electromagnetic stress tensor as a special case. The integral of the total stress field is a known expression for the macroscopic stress. As a practical example, a method is outlined for calculating stresses when the ion-electron interaction has been replaced by a pseudopotential.