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Towards sideband cooling of a single 40Ca+ ion in a Penning trap
| Content Provider | Semantic Scholar |
|---|---|
| Author | Donnellan, Sean |
| Copyright Year | 2011 |
| Abstract | This thesis presents work aimed towards achieving sideband cooling of 40Ca+ ions in a Penning trap. The observation of an increase in the number of quantum jumps as a function of the trapping magnetic field is first presented. This observation is explained by the ion falling into a long-lived D 5 2 state, out of which the ion is not being re-pumped. The ion can fall into this state due to mixing of the fine structure components with the same mJ quantum number induced by the applied magnetic field. A calculation of the mixing and shelving rate as a function of magnetic field strength is presented. This theory matches well with the experimental results observed. This work has been presented in a publication in which a perturbative analysis was used. An alternative analysis is presented here in which the full Hamiltonian is diagonalised. The essential conclusions however remain unchanged. This ‘J-state mixing’ effect means re-pumping from each of the six D 5 2 state sub-levels of our ion is required for efficient laser cooling. This is achieved by the addition of a system comprising an 854 nm laser and a fibre EOM to provide the radiation required to re-pump these levels. The same EOM is then used to re-pump out of the four sub-levels of the D 3 2 state using a single 866 nm laser. This is a great simplification of the experimental setup required to cool a 40Ca+ ion in a Penning trap which would otherwise require ten separate lasers to independently address each of the D sub-states. Achieving efficient repumping leads to the ability to perform pulsed spectroscopy on the quadrupole S 1 2 → D 5 2 transition in 40Ca+ . Preliminary results of this spectroscopy in a radio-frequency trap are presented. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://www.imperial.ac.uk/media/imperial-college/research-centres-and-groups/ion-trapping/public/Towards-Sideband-Cooling-of-a-Single-40Ca--Ion-in-a-Penning-Trap.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |