Richard Thompson

Quantum dynamics of ions in a Penning Trap

Ion traps have a proven track record of helping scientists perform some of the most precise measurements of quantum effects to date. For example, experiments in a Penning trap have measured the anomalous magnetic moment of the electron to a precision of one part in a trillion confirming the theoretical predictions of quantum electrodynamics. In our experiment, we aim to harness the ability of the Penning trap to provide very strong confinement while maintaining the motion of trapped ions free of any unwanted drive frequencies by only using static electric and magnetic fields. We then work with small ensembles or individual ions of Ca40+ to both explore the suitability of such systems for performing quantum simulation (using an analogous quantum system to simulate the behaviour of a more difficult to control system) and to observe phase transitions in small crystals of ions formed due to their mutual coulomb repulsion.

Recently we have for the first time demonstrated cooling a single Ca40+ ion to its quantum motional ground state in one dimension using a technique known as resolved sideband cooling; a task made difficult by the many laser frequencies necessary to implement this scheme. This is generally a prerequisite to performing highly sensitive coherent manipulations of the ion. Currently, we are working on extending this scheme to two or more ions.

My work on the project so far involves working on the efficient detection of such systems, both by improving the stability of the lasers used to probe the ions as well as the imaging systems used to detect the light. With these improvements, we hope to push the current trap setup to its limits, before embarking on a project to build a new trap suitable for Be9+ species that would allow us to go beyond the limits of our current system.