Research Fellows Directory
Dr Michael Tarbutt
Imperial College London
I aim to cool molecules close to absolute zero so that they can be studied in far greater detail than ever before. Molecules in a room temperature gas move at hundreds of miles per hour, rotating and vibrating in a highly disordered manner. By cooling them so that the disorder is removed, a diverse range of new physics and chemistry can be done. Using electric and optical fields, molecules can be cooled, confined and controlled. Once the temperature is below 100 milliKelvin, almost all the molecules will be in their lowest quantum states of vibration and rotation, and they are cold enough that they can be trapped forever. Such exquisite control will allow us to exploit the shape and structure of molecules to answer fundamental questions about the symmetries of space and time - do the laws of nature change if we reverse the direction of time, and are the fundamental constants changing on a cosmological timescale? For chemistry, this research will provide unprecedented control over chemical reactions. We can choose the quantum states, the energy and the orientation of the reactants, and we can apply electric and magnetic fields to turn reactions on and off or vary their rates.
As the temperature is lowered further, to a microKelvin or less, the full quantum nature of the gas of molecules is revealed. The molecules behave cooperatively and they can form ordered structures. Each molecule is sensitive to the position and orientation of every other molecule in the gas. This will be an ideal tool for simulating systems of strongly-interacting quantum particles, which are known to be at the heart of many extraordinary quantum phenomena, such as high temperature superconductivity and the fractional quantum hall effect. These are fascinating and important phenomena which are not well understood and which are far too complicated to be modelled on a computer. The gas of ultracold molecules I aim to make will allow us to study these phenomena in a highly controllable way.