Sympathetic cooling of cold molecules
Lead Research Organisation:
Durham University
Department Name: Physics
Abstract
The student is conducting experimental research in the EPSRC-recognised area of Cold Atoms and Molecules. Specifically, he is researching how to achieve sympathetic cooling of a gas of molecules into the ultracold regime through thermal contact with a much colder gas of laser cooled atoms. In order to do this, both molecular and atomic gases must be trapped in the same region of space. Unfortunately, the natural outcome of such contact between the two gases is for a chemical reaction to take place or for the molecule to change quantum state, in other words - chemistry happens. Chemistry is undesirable in this context as it leads to the molecules being lost. However, the intriguing research question is - can the chemistry be controlled?
The student will be working on the further development of a machine called a moving-trap Zeeman decelerator that can be used to load a novel magnetic trap, which he is also developing, with atoms and molecules. The novelty of the trap is that its magnetic-field profile has been tailored so as to allow, not only magnetic confinement of both gases, but the laser cooling of the atoms. It has also been designed such that the quantum state of the atoms and molecules can be manipulated by optical pumping. PW will research how to use the magnetic fields and the optical pumping to switch off the chemistry in the trap so as to allow sympathetic cooling to occur unhindered.
The student will be working on the further development of a machine called a moving-trap Zeeman decelerator that can be used to load a novel magnetic trap, which he is also developing, with atoms and molecules. The novelty of the trap is that its magnetic-field profile has been tailored so as to allow, not only magnetic confinement of both gases, but the laser cooling of the atoms. It has also been designed such that the quantum state of the atoms and molecules can be manipulated by optical pumping. PW will research how to use the magnetic fields and the optical pumping to switch off the chemistry in the trap so as to allow sympathetic cooling to occur unhindered.
Organisations
People |
ORCID iD |
| David Carty (Primary Supervisor) | |
| Paul Walker (Student) |
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N509462/1 | 01/10/2016 | 30/09/2021 | |||
| 1925385 | Studentship | EP/N509462/1 | 01/10/2017 | 30/09/2021 | Paul Walker |
| Description | In previous work our research group constructed a prototype machine for producing slow molecular beams. We have refined the operation of this machine and improved it in several ways. Our chief result is in producing detailed computer simulations of our experimental runs to enable us to interpret and explain our data. With these data in hand we are currently modifying the experiment to work with a different atomic species (hydrogen) for which we can obtain results of scientific, rather than technical, interest. |
| Exploitation Route | We are currently finishing a paper on our results so far but it is not quite ready at this time. Whilst similar machines to ours exist in a few labs around the world, all are different in the specific details of their construction and operation. Our findings will certainly be applicable to anyone interested in the research potential of slow, cold molecular beams. This could include, for example, cold controlled chemistry, quantum simulation, metrology, or constraints on new physics. We have developed a suite of software libraries for use in our simulations which are generally applicable in any area of research where interpolation of gridded data is required. This software has been published under a GPL licence and we have already had expressions of interest from a space scientist. We are also using our software techniques to design several novel types of atomic / molecular trap to advance studies in fundamental physics / chemistry. |
| Sectors | Digital/Communication/Information Technologies (including Software),Other |
| URL | https://openresearchsoftware.metajnl.com/articles/10.5334/jors.258/ |
| Description | This grant is still underway, and as it is a particularly focused technical project in the hard physical sciences it is unlikely to have a huge impact outside academia in the short-term. The technologies we are developing could well have large and difficult to predict effects in the longer term, for example: an improved understanding of chemical processes arising from studies of collision dynamics could be revolutionary in materials and manufacturing. In the much shorter term, however, we have developed a range of public outreach materials that have been presented to the public in several fora, in order to broaden public awareness and appreciation of the importance of fundamental academic research in the hard physical sciences. |
| First Year Of Impact | 2018 |
| Sector | Other |
| Impact Types | Cultural |
| Title | Three- / Four-dimensional cubic spline interpolation library |
| Description | This is a NumPy implementation of a Lekien-Marsden type 3D cubic spline interpolator. When supplied with data representing some quantity known as a set of discrete points across a spatial grid, it allows the value and derivatives of the field at arbitrary coordinates within the grid. Compared to other implementations of this method this is simple to install and heavily optimised for performance. The method has also been extended to be four-dimensional, so that E.G. time-dependent magnetic fields can be modelled. |
| Type Of Technology | Software |
| Year Produced | 2019 |
| Open Source License? | Yes |
| Impact | The improved speed of this software has allowed us to perform much more accurate simulations of our experiment in reasonable timeframes. Other groups in our university have used it, and I have been approached by an academic from another institute who was interested in using the library to interpolate data from a space mission. |
| URL | https://github.com/DurhamDecLab/ARBInterp |