Induced torque in an ellipsoid. Torque anisotropy in potassium

Abstract

We present the theory of the induced torque in a conducting ellipsoid rotating in a magnetic field. The results for compensated metals and for metals with open orbits are not strikingly different from those found in a case of a sphere. However, in a noncompensated metal with closed orbits only, large nonsaturating anisotropies appear. These can fully explain some of the torque anomalies observed in potassium. Applicable expressions for the torque are given, and the magnetic moment and charge density are discussed.