Sussex physicists’ breakthrough in the challenge to build a large scale, super-fast computer

Lasers and optics are being used to cool individual ions

A team of University of Sussex scientists have made another significant step towards the development of a large-scale, super-fast quantum computer.

A quantum computer would use the seemingly magical properties of tiny particles such as atoms to hold, process and transport vast amounts of information - all in the fraction of the time it would take a conventional computer. The same technology already provides ultra-secure communications systems, and could be used in code-breaking to reveal answers to highly-complex questions, such as how the universe was created, and in creating new medicines.

The Sussex Ion Quantum Technology Group managed to trap single 'ytterbium ions' within a very sophisticated experimental set-up that was developed to host new types of microchips that contain arrays of ion traps. Such arrays will create a "quantum memory". Ions are charged atoms and ytterbium is a special metal that will allow quantum computations to be implemented with high accuracy.

Small scale ion trap quantum computers have already been created. The next challenge lies in scaling the system to larger sizes.  The Sussex group is supported by an Engineering and Physical Sciences Research Council (EPSRC) grant to engineer and develop microchips that are then used in this setup to implement large scale quantum technology architectures. Trapping ytterbium ions in such a "chip-compatible" setup, as recently accomplished by the group, is the first step in this process of using microchips as large scale ion trap quantum processors.

In their experiment the group managed to produce trapped 'ion crystals', which consist of single ions that are held by electric fields in a regular shaped array.  These ions are laser cooled, reaching temperatures close to absolute zero, and they are held in a vacuum better than that of outer space by oscillating electric fields. The Ion Quantum Technology group at Sussex attained this result in just over three years.

Group leader Dr Winfried Hensinger, a Reader in Quantum, Atomic and Optical Physics and EPSRC Leadership Fellow, says: 'This is an amazing achievement by DPhil students James Siverns, Altaf Nizamani, Robin Sterling, Jim McLoughlin, Marcus Hughes, Bjoern Stein, Bjoern Lekitsch, all of whom have done extremely good work. The experiment also highlights the achievement of a number of undergraduate research students have been working in my group over the past three years, making this huge success possible, namely Jiddu Broersma, Merlin Bevan-Stevenson, Brendan Murray, Ben Jacques-Parr, Mark Konstantinovic, James Sayers, Philippa Young, Ben Johnson, Rajiv Ramasawmy, Kieran Lee, Dan Brown, Nik Davies, Jack Friedlander, Jessica Grove-Smith, Ben Pruess, David Scrivener and Tim Short. These undergraduate students designed and built many of the components of this sophisticated experimental setup, contributing to this world leading research.' DPhil student Robin Sterling says: 'It's the proudest moment of my academic life.'

The group is already in the process of producing the next generation of quantum computing microchips, which will be in operation soon.


Notes for editors

Dr Hensinger heads the Ion Quantum Technology Group in the Department of Physics and Astronomy at the University of Sussex (email: For details see:





By: Jacqui Bealing
Last updated: Friday, 8 January 2010