Collisions of Polar Molecules with Ultracold Alkali Metal Atoms (IP3 of EuroQUAM CoPoMol)

Lead Research Organisation: Durham University
Department Name: Chemistry

Abstract

At very low temperatures, matter enters a new regime where its properties are fully quantum-mechanical. Such quantum matter is very precisely controllable and offers many new properties that are likely to form the basis of future technologies. The EuroQUAM Programme is a EUROCORES Programme coordinated by the European Science Foundation to develop European research in Cold Quantum Matter. A major objective of the EuroQUAM programme is to achieve quantum degeneracy for polar molecules. It is already possible to slow polar molecules almost to rest using inhomogeneous electric fields and trap them at temperatures around 1 milliKelvin. However, quantum degeneracy requires considerably lower temperatures, and to achieve it for decelerated molecules it will be necessary to develop a second-stage cooling mechanism that can reach the sub-microKelvin regime. A very promising approach to this is sympathetic cooling, in which the molecules are cooled by contact with ultracold atoms. The CoPoMol proposal brings together two leading experimental groups (Berlin, London) and three theoretical groups (Durham, Warsaw, Nijmegen) to explore sympathetic cooling and to develop our understanding of atom-molecule and molecule-molecule collisions. The interplay between theory and experiment was pivotal in the creation of atomic quantum gases and will be equally crucial for polar molecules. This proposal is for a closely integrated experimental and theoretical study. The Durham work will focus on theoretical aspects of the atom-molecule collisions that are crucial for sympathetic cooling. The proposal as a whole will provide the basis for achieving condensation to form a dipolar quantum gas and pave the the way to the development of controlled ultracold chemistry.
 
Description This grant developed theory to underpin experiments aimed at cooling polar molecules by immersing them in a bath of ultracold atoms. We developed theoretical methods to handle collisions between open-shell molecules and alkali-metal atoms in magnetic fields. We developed potential energy surfaces for key systems and carried out quantum collision calculations as a function of energy and field to work out which systems were most promising for sympathetic cooling. We identified the first system (Mg-NH) for which inelastic collisions were predicted to be slow enough for sympathetic cooling to succeed.
Exploitation Route Experimental groups are currently developing experiments to achieve sympathetic cooling, using the theoretical framework and understanding that we have developed.
Sectors Digital/Communication/Information Technologies (including Software)
 
Description Our findings are being used in many laboratories around the world to develop experiments to cool molecules to the ultracold regime. The work done under this proposal underpinned the Programme Grant MMQA: Microkelvin Molecules in a Quantum Array (2010-16) and our follow-on Programme Grant application QSUM: Quantum Science with Ultracold Molecules.
First Year Of Impact 2010
Sector Other
 
Description EPSRC Programme Grant 2010
Amount £6,380,561 (GBP)
Funding ID EP/I012044/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 12/2010 
End 11/2016
 
Description CoPoMol 
Organisation Max Planck Society
Department Fritz Haber Institute
Country Germany 
Sector Academic/University 
PI Contribution We worked together to understand collisions of cold polar molecules. The role of the Durham team was to develop theoretical methods for quantum-mechanical calculations of ultracold collisions in magnetic fields, to calculate potential energy surfaces, and to carry out collision calculations on prototype systems.
Collaborator Contribution The Warsaw team developed new theoretical methods for calculating potential energy surfaces and collaborated with us to apply them to systems of interest. The Nijmegen team collaborated with us to carry out calculations on molecule-molecule collisions in magnetic fields. The Fritz Haber team developed experimental methods to cool and trap cold molecules and worked towards experiments in sympathetic cooling.
Impact All publications were associated with this collaboration, but in many cases the results were sufficiently important for the different partners to publish separately. There were nevertheless 2 joint publications on Nh-NH collisions with the Nijmegen team (Janssen, Groenenboom, van der Avoird) and several publications with the Warsaw team (Skomoriwski, Moszynski). In addition, the PDRA employed for most of the project was Piotr Zuchownski, who had completed his Ph D with the Warsaw team shortly before the project started.
Start Year 2007
 
Description CoPoMol 
Organisation Radboud University Nijmegen
Country Netherlands 
Sector Academic/University 
PI Contribution We worked together to understand collisions of cold polar molecules. The role of the Durham team was to develop theoretical methods for quantum-mechanical calculations of ultracold collisions in magnetic fields, to calculate potential energy surfaces, and to carry out collision calculations on prototype systems.
Collaborator Contribution The Warsaw team developed new theoretical methods for calculating potential energy surfaces and collaborated with us to apply them to systems of interest. The Nijmegen team collaborated with us to carry out calculations on molecule-molecule collisions in magnetic fields. The Fritz Haber team developed experimental methods to cool and trap cold molecules and worked towards experiments in sympathetic cooling.
Impact All publications were associated with this collaboration, but in many cases the results were sufficiently important for the different partners to publish separately. There were nevertheless 2 joint publications on Nh-NH collisions with the Nijmegen team (Janssen, Groenenboom, van der Avoird) and several publications with the Warsaw team (Skomoriwski, Moszynski). In addition, the PDRA employed for most of the project was Piotr Zuchownski, who had completed his Ph D with the Warsaw team shortly before the project started.
Start Year 2007
 
Description CoPoMol 
Organisation University of Warsaw
Country Poland 
Sector Academic/University 
PI Contribution We worked together to understand collisions of cold polar molecules. The role of the Durham team was to develop theoretical methods for quantum-mechanical calculations of ultracold collisions in magnetic fields, to calculate potential energy surfaces, and to carry out collision calculations on prototype systems.
Collaborator Contribution The Warsaw team developed new theoretical methods for calculating potential energy surfaces and collaborated with us to apply them to systems of interest. The Nijmegen team collaborated with us to carry out calculations on molecule-molecule collisions in magnetic fields. The Fritz Haber team developed experimental methods to cool and trap cold molecules and worked towards experiments in sympathetic cooling.
Impact All publications were associated with this collaboration, but in many cases the results were sufficiently important for the different partners to publish separately. There were nevertheless 2 joint publications on Nh-NH collisions with the Nijmegen team (Janssen, Groenenboom, van der Avoird) and several publications with the Warsaw team (Skomoriwski, Moszynski). In addition, the PDRA employed for most of the project was Piotr Zuchownski, who had completed his Ph D with the Warsaw team shortly before the project started.
Start Year 2007