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An experimental condensed matter physicist who, with Gene Dresselhaus and Charles Kittel, studied cyclotron resonance in silicon and germanium. Their 1955 work used single crystals near 4 K, light modulation and circularly polarized microwaves. Changing the orientation revealed direction-dependent band effective masses of electrons and electron holes, allowing measurements to reconstruct the shapes of constant-energy surfaces near the edges of energy bands.^[ref]

Charles Kittel and Malvin Ruderman calculated how conduction electrons mediate an interaction between nuclear magnetic moments. A nuclear moment perturbs the electron system, whose response in turn acts on another nuclear moment: the nuclei need not interact only through their direct magnetic coupling. Their 1954 calculation connected this indirect interaction with nuclear magnetic resonance line widths in silver and discussed predictions involving different isotopes. This is an early example of extracting information about collective electronic response from a magnetic resonance measurement.^[ref]

His research with Malvin Ruderman helped explain conduction-electron-mediated exchange. Berkeley collects recollections of his research and teaching: physics.berkeley.edu/node/808.

By Gene Dresselhaus, Arthur F. Kip and Charles Kittel. Physical Review 98, 368–384.

Publisher: doi.org/10.1103/PhysRev.98.368

The abstract describes single-crystal cyclotron resonance measurements near 4 K, light modulation, circularly polarized microwaves and directional anisotropy of carrier energy surfaces.

Gene Dresselhaus, Arthur F. Kip and Charles Kittel used cyclotron resonance to investigate electrons and holes in silicon and germanium crystals. Their 1955 measurements near 4 kelvin combined light modulation with circularly polarized microwaves and changes in the crystal orientation relative to the magnetic field. The directional dependence of the resonance revealed anisotropic carrier effective mass values and the shape of constant-energy surfaces near the edges of the electronic band structure. The experiment turns the orbital motion of charge carriers into a probe of electronic band structure.^[ref]

With Charles Kittel, he calculated conduction-electron-mediated exchange between nuclear magnetic moments. His later research included neutron stars. Columbia's account of his career also recalls his enthusiasm for order-of-magnitude teaching.^[ref]