Simon Stellmer receives ERC Starting Grant

Simon Stellmer, nuClock researcher on the Vienna team, has received an ERC Starting Grant. The title of his project reads “Ultracold mercury for a measurement of the EDM”. Within this project, he will address one of the most fundamental questions in all of physics: Why does the Universe contain matter? Shortly after the Big Bang, many billion years ago, equal amounts of matter and antimatter were formed. These two types of matter, however, destroy themselves when they come into contact. This process is called annihilation, and naively, one would conclude that matter and antimatter annihilated completely some time after the Big Bang. Quite obviously, this conclusion is at odds with observations.

So there must be a fundamental asymmetry between matter and antimatter: an underlying mechanism that favors matter over antimatter. This mechanism ensured that, as matter and antimatter annihilated, a small excess portion of matter survived: this is the matter that forms our Universe today. The details of this mechanism, however, are still a mystery.

The asymmetry between matter and antimatter is connected to a phenomenon called CP-violation, which, in short, states that going backwards in time is not the same as going forward in time. This phenomenon shows up as a tiny tiny ellipticity of fundamental particles (electrons, neutrons and the like): the charge distribution of these particles is not perfectly spherical, but a little deformed. This deformation can be measured in high-precision measurements. A number of such experiments were carried out already, but none of them was sensitive enough to detect these small deformations. Dr. Stellmer aims to improve the sensitivity of these experiments by taking them into the quantum world: previous experiments were performed with room-temperature gases of mercury atoms. He will now cool these gases to temperatures one millionth of a degree above absolute zero: this is where quantum phenomena emerge, which Dr. Stellmer seeks to exploit for improving the measurement performance.

ERC Grants are among the most prestigious prizes awarded to researchers in Europe. The project will be funded with 2 M€ by the European Union.

Dr. Stellmer received a prestigious ERC grant.

The press release is available in here.