Research team
Expertise
Most of my research experience is in the field of theoretical condensed matter physics. I have started my research career by theoretically modelling a high-pressure experiment on metallic hydrogen, and most of my further research has been at least partially inspired by metallic hydrogen or high-pressure hydrides. For example, I have investigated the optical response of metallic nanospheres with a smooth electron density on the edge, which can be used as pressure sensors in high-pressure metallic hydrogen experiments. Since 2019 I have been studying the large polaron, a quasiparticle that is formed when an electron in a solid interacts weakly with the ions (or equivalently, the phonons) of that solid. Specifically, I investigate the effect of anharmonicity on such polarons. In my PhD thesis, an additional anharmonic interaction term in the Fröhlich Hamiltonian is derived, which represents the interaction of the electron with 2 longitudinal optical phonons. The model is simplified enough so that this interaction depends on only 1 additional material parameter. Several of the single polaron properties were investigated analytically in terms of this new anharmonic material parameter: the binding energy, the effective mass, the optical absorption spectrum, and the possibility of bipolaron formation.
Modelling of thermo-optical properties of hydrogen at extreme pressures.
Abstract
Hydrogen is the simplest element in the universe. When it is at room temperature and atmospheric pressure, hydrogen takes the form of a gas. One can cool or pressurize this gas to turn it into a solid. Under these conditions, the solid hydrogen is an electrical insulator. However, nearly a century ago, it was predicted that putting a pressure of a quarter of a million times atmospheric pressure on solid hydrogen would turn it into a metal. This material was called metallic hydrogen, and physicists have been trying to create it ever since it was predicted to exist. Theoretical predictions also indicate that metallic hydrogen is a room-temperature superconductor, meaning that it can transport electricity without losses. Additionally, it would be a very powerful rocket fuel, and it would remain metallic even when the pressure is taken off. Recently, experiments by the Silvera research group at Harvard University indicate the first creation of metallic hydrogen in the lab. However, other research groups do not agree with this claim. In the proposed research, we attempt to theoretically model the experiment used by the Silvera research group to get a correct interpretation of their results. Furthermore, we will use this model and the experimental results to estimate material parameters of metallic hydrogen. Finally, we will theoretically develop an experiment that can measure whether the metallic hydrogen in the experiments is superconducting, as predicted by theoryResearcher(s)
- Promoter: Tempere Jacques
- Fellow: Houtput Matthew
Research team(s)
Project type(s)
- Research Project