Carson Dunning Jeffries (March 22, 1922 – October 18, 1995) was an American physicist.
The National Academies Press said that Jeffries "made major fundamental contributions to knowledge of nuclear magnetism, electronic spin relaxation, dynamic nuclear polarization, electron-hole droplets, nonlinear dynamics and chaos, and high-temperature superconductors."
He was noted for being the first to observe the isotropic spin-spin exchange interaction in metals (also known as the Ruderman-Kittel interaction).
He also discovered methods for the dynamic nuclear polarization by saturation of forbidden microwave resonance transitions in solids.
He also discovered the existence of giant electron-hole droplets in semiconductors.
He was a member of the U.S.
National Academy of Sciences and the American Academy of Arts and Sciences.