Researchers Demonstrate Optical Cycling in Thorium Monoxide for Improved Fundamental Physics Tests
Scientists have successfully demonstrated optical cycling—repeated excitation and emission of photons—in thorium monoxide (ThO) molecules for the first time, a technique previously limited to simpler atomic systems. This advance could improve the sensitivity of experiments measuring the electron's electric dipole moment, a key test of fundamental symmetries in physics. The technique could enhance detection efficiency by over fourfold and statistical sensitivity by more than twofold in such precision measurements.
Researchers have achieved the first demonstration of optical cycling in thorium monoxide (ThO), a non-conventional molecule used in precision tests of fundamental physics. The team showed that both J=1 and J=2 rotational levels of ThO can cycle approximately 11 photons on average before losing population to other vibronic states, with scattering rates around 2 million photons per second. This capability could significantly enhance the ACME experiment, which searches for the electron's permanent electric dipole moment—a sensitive probe of physics beyond the Standard Model. The demonstrated optical cycling scheme could be extended to scatter about 100 photons, enabling broader quantum control and sensing applications. The improvement in detection efficiency and statistical sensitivity represents a meaningful advance for precision tests of fundamental symmetries.
What different sources said
- arXiv physicsCenter
Photon Cycling and Laser Cooling of an Asymmetric Top Molecule
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