Advanced atomic clock makes better dark object detector

District researchers have used state-of-the-art atomic clocks to narrow down the discovery of the insidious dark matter, the value of clocks that are constantly being improved beyond the time limit.

Older atomic clocks operating at microwave frequencies have previously hunted for dark matter, but this is the first time that a new clock, operating at higher optical frequencies and an ultra-stable oscillator to ensure stable light waves, has been set to set more precise boundaries. On search. The research is described Physical Review Letters .

Astrophysical observations show that dark matter forms most of the “material” in the universe but has yet to be captured. Researchers around the world are looking for it in various forms. The GIL team focused on ultralight dark matter, which in theory is a juvenile mass (much less than a single electron) and a massive wavelength – how far a particle travels in space – can be as large as the size of dwarf galaxies. This type of dark matter will be bound by gravity to galaxies and therefore to normal objects.

Ultralight dark matter is expected to create small fluctuations in two basic physical “static”: a mass of electrons, and a fine-structure stable. The JIL team used the Strontium lattice clock and the Hydrogen Measure (microwave version of the laser) to compare their known ical particles and microwave frequencies, respectively, with the corresponding light frequency in an ultra-stable cavity made from a single crystal. Pure silicone. The resulting frequency ratios are both sensitive to variation over static time. Relative fluctuations in ratio and stability can be used as sensors to combine cosmological models of dark matter with accepted physics principles.

The GILA team set a new limit on the floor for “normal” fluctuations, which may be due to any unusual signs of a dark object detected later. The researchers stabilized the binding strength of the ultralight dark matter to have an electron mass and a fine-structure of 10.^-5 Or less, the most accurate measure of this value.

GIL is run jointly by the National Institute of Standards and Technologies (GIS) and the University of Colorado Boulder.

“No one really knows at what level of sensitivity you would start to see dark matter in laboratory parameters,” said NIST / GILA Fellow Jun Ye. “The problem is that physics we know it’s not complete at the moment. We know something is missing, but we don’t know much about how to fix it yet.”

He added, “We know that dark matter exists from astrophysical observations, but we do not know how dark matter relates to ordinary matter and the values ​​we measure.” “Experiments like ours allow us to test samples of different theories put together to explore the nature of dark matter. By setting better and better limits, we hope to find some false theory models and eventually discover them in the future.”

Scientists are not sure if the dark matter contains particles or oscillating fields affecting the local atmosphere, he noted. He said GILA experiments are aimed at finding the “pulling” effect of dark matter on common matter and electromagnetic fields.

Atomic clocks are the main test for dark matter as they can detect changes in basic stability and are rapidly improving in accuracy, stability and reliability. The stability of the cavity was also a decisive factor in the new criteria. The frequency of light resonance in a cavity is based on the length of the cavity, which can be found in the Bohr radius (the same physical constant of the distance between the nucleus and the electron in a hydrogen atom). The Bohr radius is also related to the values ​​of streamlined formation and static electron mass. Therefore, a change in the resonant frequency relative to the transition frequency in the molecule may indicate fluctuations in these stationary spots due to the dark matter.

The researchers collected data with a clock clock of 30% time on the frequency ratio of the strontium / cavity for 12 hours, resulting in a data set of 978,041 seconds long. Hydrogen Measure with Data Measure lasts for 94 days, resulting in a record 2,826,942-second. The frequency ratio of hydrogen / cavity provides useful sensitivity to the electron mass although the measure was less stable and produced louder signals than the strontium clock.

JILA researchers collected dark matter search data during their recent demonstration – which includes data from multiple atomic clocks to generate a single, highly accurate time-keeping signal for system distribution. As the performance of atomic clocks, optical cavities and time scales improves in the future, the frequency ratio can be re-tested with always-higher resolution, advancing the detection of dark objects.

“Any time an optical atom operates a time scale, there is an opportunity to determine something new or to discover a dark object,” he said. “In the future, when we can put these new systems into orbit, it will be the largest ‘telescope’ ever built to detect dark matter.”