First Spectroscopy of Antihydrogen with Laser-Cooling assisted Antihydrogen Trapping

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Antimatter lies at the heart of one of the most profound mysteries in our current understanding of the universe. Since the discovery of quantum mechanics, the description of the very small, and Einstein's general relativity theory, the description of the very large, the two have been at odds with each other. Quantum mechanics predicts the existence of a mirror image of matter, the so-called antimatter, which was soon confirmed. However, quantum mechanics also predict that the universe should be symmetric with respect to matter and antimatter or in other words that half the universe should be made of antimatter. Until now we have found no evidence of bulk antimatter in the universe a fact that remains a mystery in science. This is where Einstein may perhaps enter the stage. Einstein's theory describes the development of the very large (stars, galaxies, the universe) very well, but it is not compatible with the quantum world. A description of our world capable of encompassing both the very large and the very small has thus far eluded science. Such a description will have to include an explanation for the apparent lack of antimatter in the universe.The recent start up of the LHC forms part of the effort to address this fundamental problem in our understanding of the world around us. This fellowship forms part of another, low energy, approach to the same issue. We are working towards detailed studies of the structure of neutral atoms made of antimatter. According to quantum mechanics their structure should be exactly the same as their matter counterparts. To accomplish this goal we are trapping Antihydrogen and plan to compare it to Hydrogen. As quantum mechanics predicts that these atoms should have identical internal structure to any level of precision, any difference we may discover will deliver ground-breaking information for our understanding of the universe. The making and trapping of these anti-atoms is a delicate affair, and the work here builds on many years of experience in the production of Antihydrogen and the recent successful trapping of the same. The motivation for making atoms is that these are neutral and can be probed by one of the best precision tools available to science - lasers. Precise measurements on atomic systems have been perfected over the last century and the advent of lasers accelerated the field far beyond other fields of precision measurement, such that today, we can measure transitions in atoms with up to 17 decimal places of precision. We plan to apply the techniques with this unfathomable precision to study our trapped Antihydrogen atoms.However, this lofty goal requires very precise control over the formation of the Antihydrogen. The Antihydrogen must be trapped to allow for precise measurements of its internal structure. As Antihydrogen is neutral, it cannot be easily trapped. However, we can trap Antihydrogen in a magnetic trap. This is possible as Antihydrogen, though neutral, has a structure, which causes it to have a small magnetic moment, or in other words behave as a very small magnet. The tricky bit to trapping the Antihydrogen is that this dipole moment is so small, that even with state-of-the-art magnetic fields, our trap can only hold atoms so slow that their energy corresponds to a temperature less than half a degree above absolute zero. We are therefore currently only able to trap about one atom at a time. This project aims to facilitate the production of very cold Antihydrogen by using Beryllium ions, which can be cooled using a technique called laser-cooling. These ions can be cooled to a few thousandth of a degree above absolute zero, and can thus be used as a heat sink for the particles used to form Antihydrogen. We expect that this effort could significantly increase the number of trapped atoms and allow us to study the differences between Antihydrogen and Hydrogen in great detail. If any difference is found it will have a profound impact on physics as we know it.