Isidor Isaac Rabi
1898–1988, Rymanów, Galicia, Austria-Hungary (now Poland), New York City, United States
Austrian-American physicist who invented the molecular-beam magnetic resonance method for precisely measuring the magnetic properties of nuclei.
Rabi was born in Rymanów, Galicia, but raised in New York. He studied chemistry at Cornell and Columbia, then spent two formative years in Europe studying with the masters of quantum mechanics — Sommerfeld, Bohr, Pauli, Heisenberg, Stern — before joining Columbia in 1929, where he stayed for his entire career and built the department into a leading center of physics. During the war he was associate director of MIT's Radiation Laboratory developing radar; after the war he co-founded Brookhaven National Laboratory and helped establish CERN.
Nobel-winning work
In 1937–38 at Columbia, Rabi, with Jerrold Zacharias, Sidney Millman and Polykarp Kusch, combined Otto Stern's deflection of molecular beams in inhomogeneous magnetic fields with resonance induced by a radio-frequency field. When the radio field matched the nuclei's Larmor frequency in a uniform magnet, the nuclei flipped their spins and the beam deflected — enabling measurement of nuclear magnetic moments with unprecedented precision. This 'molecular-beam magnetic resonance method' yielded precise values for the magnetic moments of the proton and deuteron and revealed the deuteron's electric quadrupole moment — evidence that the nuclear force is not purely central.
The method became the foundation of atomic clocks, nuclear magnetic resonance and the hydrogen maser; the 1944 Nobel Prize in Physics honored Rabi 'for his resonance method for recording the magnetic properties of atomic nuclei'.
Workplaces: Columbia University
United States