Optical transition of the 229Th nucleus in a solid-state environment
Abstract
We describe a novel approach to directly measure the energy of the narrow, low-lying isomeric state in 229Th. Since nuclear transitions are far less sensitive to environmental conditions than atomic transitions, we argue that the 229Th optical nuclear transition may be driven inside a host crystal with a high transition Q. This technique might also allow for the construction of a solid-state optical frequency reference that surpasses the precision of current optical clocks, as well as improved limits on the variability of fundamental constants. Based on analysis of the crystal lattice environment, we argue that a precision of 3×10-17< f/f <1×10-15 after 1 s of photon collection may be achieved with a systematic-limited accuracy of f/f 2 × 10-16. Improvement by 102-103 of the constraints on the variability of several important fundamental constants also appears possible.