Coherent Spectroscopy on a Single Atomic System at Rest in Free Space III

Abstract

When I gave the first talk under this title in 1976 at the second of these symposia (below referred to as II), serious mono-particle spectroscopy had just arrived on the scene with a precision measurement of the g-factor of an individual electron by the Seattle group. This experiment, published under the title Axial, magnetron, cyclotron and spin-cyclotron-beat frequencies measured on single electron almost at rest in free space (geonium), already made use of an early rf variant of sideband cooling. At II I also discussed the 1973–75 abstracts Proposed 10¹⁴ ΔV < V Laser Fluorescence Spectroscopy on Thallium ⁺ Mono-ion Oscillator I–III, which went on to “electron shelving” and laser side band cooling. Prior to 1973, impressive spectral resolution had been attained in Seattle, NASA, Bell, and Bonn-Mainz studies of hfs resonances in clouds of trapped He⁺, H₂ ⁺, Hg⁺ ions in Paul rf traps, and of cyclotron and spin resonances in clouds of electrons in Penning traps. Historically, spectra of electrons trapped in vacuum were observed first. A 1961 progress report to the NSF detailed the observation of cyclotron, magnetron and axial resonances on small clouds in a Penning trap in Seattle. Thus many of the techniques and procedures now widely used for trapped charged and neutral atoms were first proposed or exercised for electrons. Even so, no individual neutral atom has been isolated to date.