Participants in the QGates Network

National Physical Laboratory

Team leader

Prof. P. Gill

Expertise and experience of the participating organisation

The NPL ion trapping group has built on its long-standing expertise in single trapped ion research for next generation frequency standards by developing the capability and techniques to enable the preparation and control of well-prepared quantum states of the trapped ion within an isolated environment, protecting against decoherence. This has been achieved through the use of the single ion within an end-cap structure which has allowed good cooling and micromotion control in 3 dimensions, with trap storage times of several months as necessary. In addition it has developed, and continues to improve, narrow linewidth sources for cooling and probing the trapped ion's quantum state both in the weak and intense field regimes. Solid state and diode linewidths in the region of a few kHz down to a few tens of Hz have been developed, and resulting cold ion widths for the quadrupole and octupole transitions of ~ 190 Hz and ~ 4.2 kHz respectively have been observed. The group remains the only group worldwide to have observed the ultra weak octupole transition in ytterbium, by means of quantum jump analysis. Experiments are currently underway with 171Yb+ /172Yb+ and with 88Sr+ in end-cap traps, and with 87Sr+/88Sr+ combinations in miniature Paul traps.

Relevant recent publications

  • "Kilohertz resolution spectroscopy of the 2S1/2 - 2F7/2 electric octupole transition in a single 171Yb+ ion" SA Webster, P Taylor, M Roberts, GP Barwood and P Gill, Phys Rev A (2002) in press.
  • "Improved three-dimensional control of a single strontium ion in an endcap trap" AG Sinclair, MA Wilson and P Gill Opt. Commun. (2001) vol 190, 193-203.
  • "Resolved sideband cooling in a single trapped strontium ion" AG Sinclair, MA Wilson, V Letchumanan and P Gill Proc. 6th Sympsium on Frequency Standards & Metrology Ed P Gill, World Scientific (2002) in press.
  • "Observation of the 2S1/2 - 2F7/2 electric octupole transition in a single 171Yb+ ion" M Roberts, P Taylor, GP Barwood, WRC Rowley and P Gill Phys. Rev. A (2001) vol 62, 020501(R).

    Involvement in other EC projects

    The NPL group is currently a member of the QUBITS (QIPC RTD) consortium.

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