Test of the linearity of quantum mechanics in an atomic system with a hydrogen maser
Ronald Lee Walsworth, Isaac F. Silvera, Edward M. Mattison +1 more
We extend a nonlinear generalization of quantum mechanics, recently formulated by Weinberg, to systems of composite spin, such as atoms. We have used hydrogen (H) masers to set a limit of 3.7\ifmmode\times\else\texttimes\fi{}${10}^{20}$ eV (8.9 \ensuremath{\mu} Hz) on the magnitude of a nonlinear correction to the quantum mechanics of atomic spins. This result is of comparable magnitude to the limit recently set in a single-valued (nuclear) spin system. In the absence of nonlinear effects, the experiment provides a new and stringent test of H-maser clock performance and the applicability of standard maser theory.
Physical Review Letters•May 28, 1990•61 citations