Charge delocalisation and hopping in an ultra-cold atomic lattice
Lead Research Organisation:
Durham University
Department Name: Physics
Abstract
Using lasers, a cloud of atoms can be cooled to within a millionth of a degree above absolute zero. Atoms that are this cold hardly move at all, and they can be trapped using laser beams to make a crystal of regularly spaced atoms held in place by light, known as an optical lattice. The aim of this project is to study what happens when we excite the electrons in these atoms to high energies using a pulse of laser light. Normally the electrons in an atom orbit close tothe nucleus, but if we give the outermost electron more and more energy, its orbit gets larger and larger. Eventually the electron orbits of neighbouring atoms in the lattice begin to overlap, and the electrons no longer belong to a particular atom and can spread out along the lattice. This concept is important in many areas of physics, for example in explaining how the electrons in a metal free themselves to form an electrical current. The advantage of studying this with ultra-cold atoms trapped in an optical lattice is that the properties of each of the atoms in thelattice can be controlled extremely precisely. For example using a laser beam an electron can be removed from just one atom in the lattice, leaving behind a single positively charged ion. An electron from a neighbouring atom can then ``hop'' across to replace the lost electron, leaving behind an ion in its turn. Studying how electrons hop from atom to atom is one of the goals of this proposal.
Publications
Bridge E
(2009)
A vapor cell based on dispensers for laser spectroscopy
in Review of Scientific Instruments
Javaux C
(2009)
Modulation-free pump-probe spectroscopy of strontium atoms
Javaux C
(2010)
Modulation-free pump-probe spectroscopy of strontium atoms
in The European Physical Journal D
Lochead G
(2013)
Number-resolved imaging of excited-state atoms using a scanning autoionization microscope
in Physical Review A
Mauger S
(2007)
Spectroscopy of strontium Rydberg states using electromagnetically induced transparency
in Journal of Physics B: Atomic, Molecular and Optical Physics
Millen J
(2010)
Two-electron excitation of an interacting cold Rydberg gas.
in Physical review letters
Millen J
(2011)
Spectroscopy of a cold strontium Rydberg gas
Millen J
(2011)
Spectroscopy of a cold strontium Rydberg gas
in Journal of Physics B: Atomic, Molecular and Optical Physics
Mukherjee R
(2011)
Many-body physics with alkaline-earth Rydberg lattices
in Journal of Physics B: Atomic, Molecular and Optical Physics
Vaillant C
(2012)
Long-range Rydberg-Rydberg interactions in calcium, strontium and ytterbium
in Journal of Physics B: Atomic, Molecular and Optical Physics
Description | We laser-cooled strontium atoms and created a Rydberg gas for the first time. We were the first to create a cold gas of doubly excited atoms. We also clauclated some of their properties. |
Exploitation Route | Underpin growing area of research on two-electron Rydberg atoms |
Sectors | Education Other |
URL | https://www.jqc.org.uk/research/two-electron-rydberg-systems/ |
Description | Used by other research groups to advance state of the art in the field |
First Year Of Impact | 2007 |
Sector | Education,Other |
Impact Types | Cultural Societal |
Description | EPSRC |
Amount | £596,000 (GBP) |
Funding ID | EP/J007021/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 06/2012 |
End | 07/2016 |
Description | Collaboration on two electron Rydberg atoms with MPIPKS Dresden (Pohl group) |
Organisation | Max Planck Society |
Department | Max Planck Institute for the Physics of Complex Systems |
Country | Germany |
Sector | Academic/University |
PI Contribution | Start of a collaborative project on the theory of many-body physics with two-electron atoms |
Start Year | 2010 |