Magnetic Moment of a Solid-State Plasma

Abstract

This report is concerned with the magnetic moment $M$ of a plasma consisting of holes and electrons generated by light within a cylindrical semiconductor crystal immersed in a magnetic field. Macroscopic transport equations have been used to derive the dependence of $M$ on field strength, mobility, and surface recombination conditions. In the limits of low and high surface recombination, the theoretical result demonstrates the transition between transverse equilibrium ($M=0\mathrm{}$) and pure magnetic confinement ($M=-\frac{\mathrm{nkT}}{B}$). Experiments using germanium and an inhomogeneous magnetic field directly measured the diamagnetic force exerted by the plasma on its scattering medium. An induction method utilizing a uniform magnetic field of strength up to 70 kG gave collateral results. The dependence of the moment on magnetic field strength, light intensity, temperature, and surface recombination velocity support the theory.