Penning (IONPEN)

The goal of IONPEN is to investigate scalable quantum simulation and computation based on two-dimensional arrays of ions trapped in a micro-fabricated planar Penning trap operated at cryogenic temperatures. A Penning trap differs from a radiofrequency (R.F.) trap (also known as a Paul trap) in that the former uses static electric and magnetic fields to confine charged particles while the latter uses a combination of static and oscillating electric fields. Paul traps have to date been the widely popular choice for trapped ion quantum information experiments, demonstrating high precision quantum control over around 50 ions in a single large trap. The use of R.F. potentials, however, makes it inherently possible to realise only linear chains of ions, and ions trapped via R.F. potentials generally exhibit small, uncontrolled oscillations caused by misalignment of the null points in the static and oscillating electric fields. These oscillations interfere with the techniques used to control the qubit.

Most contemporary Penning traps used for quantum information experiments are made of cylindrical electrodes that create a single trapping well. It is possible to generate the required static electric trapping potentials via a 2-D micro-fabricated surface instead of a cylinder, and trap a 2-D lattice of ions above the surface of the trap with each ion in its own potential well. The major advantage of trapping in a planar trap versus trapping in a cylindrical trap is that the planar trap’s multi-well trap potentials control individual ions, while a cylindrical trap’s single-well potentials can only address the bulk ion crystal.

Micro-fabrication techniques, similar to those used in the TIQI group for Paul traps, will allow for the generation of surface electrode structures that create the required array of quadrupole potential wells. These potentials combined with a high magnetic field should make it possible to generate arbitrary 2-D lattices of strongly interacting ions, and standard laser control techniques employed in the trapped ion community make such a system an ideal platform for studying many-body interactions, such as the 2-D quantum Ising spin model. Moreover, dynamical changes to the electric potential should allow for movement of ions between any two possible trap sites. Such reconfigurable arrays could potentially form the basis for a scalable trapped ion quantum computing architecture.

IONPEN is supported by an ERC Consolidator Grant, and the design commenced in early 2019. More details on our plan for using micro-fabricated penning traps for quantum simulation and computation can be found external pagehere

tiqi-penning-ionpen
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