A team of physicists led by Professor Stephan Schiller Ph.D. from Heinrich Heine University Düsseldorf (HHU) has made groundbreaking progress in ultra-high-precision laser spectroscopy on a simple molecule. They have measured the wave-like vibration of atomic nuclei with unparalleled accuracy, confirming the established force between atomic nuclei without any deviations.
For nearly a century, researchers have focused on precision investigations of simple atoms, particularly the hydrogen atom, which has the most precisely computed energies and electromagnetic spectrum of a bound quantum system. Comparing theoretical predictions with extremely precise measurements allows them to test the underlying theories.
These tests are crucial as scientists worldwide are searching for evidence of new physical effects caused by Dark Matter, but so far, no discrepancies have been found between measurements and predictions.
In contrast to hydrogen atoms, the simplest molecule, the molecular hydrogen ion (MHI), had not received much attention until now. Professor Stephan Schiller’s research group at HHU has dedicated itself to this topic and developed cutting-edge experimental techniques, making them among the world’s most accurate.
The molecular hydrogen ion (MHI) consists of three particles: H2+, comprising two protons and an electron, and HD+, with a proton, a deuteron (a heavier hydrogen isotope), and an electron. The components within the molecule can exhibit various behaviors, with electrons moving around the atomic nuclei and the atomic nuclei vibrating against or rotating around each other, behaving like waves, as described by quantum theory. The team’s work has shed new light on these wave motions within molecules.
In the realm of physics research, studying the spectra of molecules has become an intricate art. These spectra, represented by various spectral lines, provide valuable insights into molecular motion modes. Unlike atom spectra, molecular spectra are more complex and require highly precise measurements and calculations based on quantum theory.
At Heinrich Heine University Düsseldorf (HHU), Professor Stephan Schiller’s team has been at the forefront of laser spectroscopy on the molecular hydrogen ion (MHI). They have continuously improved experimental techniques, achieving remarkable resolutions in spectral measurements. By precisely comparing experimental data with theoretical predictions, any potential deviations from established theories can be detected, offering clues for possible modifications.
The physicists at HHU utilize an ion trap in an ultra-high vacuum container to confine around 100 MHI. Laser cooling techniques bring the ions to an incredibly low temperature of 1 milli Kelvin, enabling extremely accurate measurement of rotational and vibrational transitions in the molecular spectra. Their recent breakthrough includes measuring a spectral line with a wavelength of 1.1 μm in Nature Physics.
Professor Schiller emphasizes that their experimental results agree with theoretical predictions, leading to the most precise test of charged baryons’ quantum motion. Any deviation from established quantum laws, if present, must be smaller than 1 part in 100 billion.
The results also hold implications for Dark Matter research. While no evidence of a new fundamental force between the proton and deuteron has been found, the search continues. Such a hypothetical force could be linked to Dark Matter, but for now, their experiments have ruled out its presence within the tested parameters.
Source: Heinrich-Heine-Universität Düsseldorf