Novel Ion Traps for Quantum Simulation and Quantum Computation

In the rapidly growing field of quantum technology based on trapped ions, their internal and external degrees of freedom are typically manipulated using laser radiation. Moreover, the building of a large-scale architecture and... [ view full abstract ]

In the rapidly growing field of quantum technology based on trapped ions, their internal and external degrees of freedom are typically manipulated using laser radiation. Moreover, the building of a large-scale architecture and scaling of laser-based qubit operations to a large number of ions remains a challenging goal. Here we present recent results achieved in our group, in which the operation and characterization of novel scalable surface-electrode ion traps based on the near-field gradient approach [1-4] is the central focus. At first the ion trapping and microwave control of the hyperfine states on laser cooled ⁹Be⁺ ions trapped 70 µm above a single-layer ion trap is presented. In such a trap we demonstrate motional-sideband ground state cooling via laser and microwave radiation. Towards the realization of multi-qubit gates using the microwave approach, we also characterize motional heating rates of the individual radial frequency modes and share modes of a pair of ions. On a second part, the operation of a novel trap with integrated multilayer microwave conductors is described. This trap has been fabricated with a more elaborated multilayer method capable of integrating several thick-metal and planarized thick-dielectric-layers [5]. In addition, this new trap not only features the necessary set of conductors to induce single and multi-qubit quantum operations but also generates a low residual field and a high magnetic field gradient at the position of the ions. We finally discuss new routes towards realizable applications in the field of quantum technology based on trapped ions using microwave radiation.

Fig 1. SEM micrograph of the central part of a multilayer ion trap with integrated 3D meander-like structure. (left inset) bottom and upper metal electrodes separated by a thick (10 µm) dielectric layer. (right inset) EMCCD fluorescence signal of ⁹Be⁺ ions trapped at 35 µm above the trap.

[1] C. Ospelkaus et al., Nature 476, 181 (2011).

[2] C. Ospelkaus et al., Phys. Rev. Lett. 101, 090502 (2008).

[3] M. Carsjens et al., Appl. Phys. B 114, 243 (2014).                                    

[4] M. Wahnschaffe et al., Appl. Phys. Lett. 110, 034103 (2017).

[5] A. Bautista-Salvador et al, in preparation