A team of researchers used a revolutionary technique to uncover previously unknown properties of technologically important silicon crystals, and as a result, they discovered new information about an important subatomic particle and the fifth force of nature. The journal Science writes about this.
The study was conducted as part of an international collaboration at the National Institute of Standards and Technology (NIST). Dmitry Pushin, a member of the Institute of Quantum Computing at the University of Waterloo and lecturer in the Department of Physics and Astronomy, was the only Canadian researcher to participate in the study. Pushin’s goal was to create high-quality quantum sensors from perfect crystals.
By directing subatomic particles – neutrons – to silicon crystals and tracking the result with high sensitivity, the researchers were able to obtain three outstanding results: the first in 20 years to measure a key property of a neutron using a unique method; high-precision measurements of the effects of thermal vibrations in a silicon crystal; and limiting the strength of a possible fifth force beyond standard physical theories. The latest work, carried out in collaboration with researchers from Japan, the United States and Canada, has quadrupled the measurement accuracy of processes in the structure of a silicon crystal.
Pushin, whose research focuses on neutron physics and interferometry, was instrumental in the collection of neutron data and chemical etching of samples. This helped the research team explore the forces beyond the Standard Model.
The Standard Model is now a widely accepted theory of the interaction of particles and forces at the micro level. But this is an incomplete explanation of how nature works, and scientists suspect there is more to the universe than theory describes. The Standard Model describes three fundamental forces in nature: electromagnetic, strong and weak nuclear forces. Each force acts through the action of “carrier particles”. For example, a photon is a carrier of electromagnetic force. But the Standard Model does not include gravity in its description of nature. In addition, some experiments and theories suggest the possible presence of a fifth force.
Researchers are already planning larger-scale measurements of the Pendellosung effect using silicon and germanium. Scientists expect a fivefold decrease in the error of their measurements, which can give the most accurate measurement of the radius of a neutron charge to date and detect the very fifth force. They also plan to conduct a cryogenic version of the experiment that will show how the atoms of the crystal behave in the quantum ground state. It is this that explains the fact why quantum objects are never completely motionless, even at temperatures close to absolute zero.