Experiments with Trapped Ions in Microstructured Traps
Universität Mainz, Germany
I report about two recent experiments from the Mainz ion trapping group, where the shuttling capabilities of microstructured segmented Paul traps are harnessed. I will start by briefly outlining our experimental platform. I will then present measurements where two spin qubits are entangled, separated and shuttled to separate trap segments. Based on this, we show that entangled, separated qubits can be used to map out the quantizing magnetic field along a large distance range. We find that for odd Bell states, entanglement persists for separation distances as far as about 5mm and hold times as long as 20ms. However, we observe slow drifts of the Bell state phase for separated ions. We therefore see an unexpected source of decoherence, which needs to be controlled in order to pave the way for scalable quantum computing with a trapped-ion platform.
The second topic I will talk about is the control and usage of phase-stable free-space standing waves, i.e. optical lattices, for trapped ions. I first show how we establish control over the absolute optical phase of a standing wave on short timescales. I will then present results from a first application of this technique. First, I show how the standing wave is employed as a ruler for measuring the localization of the ion with 6nm accuracy over a range of 120um, which allows for mapping out the electric fields generated by the trap electrodes. Second, I show how optical kicks can be used in conjunction with electrical kicks to apply phase-controlled displacement operations. Finally, I will discuss ideas for possible future applications.
College Park, MD 20742