Towards an all-electronic microwave-enabled trapped electron quantum computer

We explore electrons trapped in Paul traps as an attractive alternative to trapped ions to process quantum information. The combination of their extremely light mass and simple two-level spin structure enables high-speed operation while allowing for high-fidelity operation, and they can be manipulated with well-established microwave technology, removing some of the optical engineering challenges required to build a large-scale trapped-ion quantum computer.

Towards this goal, we trap single to few electrons in a millimeter-sized quadrupole Paul trap driven at 1.6 GHz in a room-temperature ultra-high vacuum setup. Electrons with sub-5 meV energies are introduced into the trap by near-resonant photoionisation of an atomic calcium beam and confined by microwave and static electric fields for several tens of milliseconds. A fraction of these electrons remains trapped longer and show no measurable loss for measurement times up to a second. Electronic excitation of the motion reveals secular frequencies which can be tuned over a range of several tens to hundreds of MHz.

Operating an electron Paul trap in a cryogenic environment may provide a platform for all-electric quantum computing with trapped electron spin qubits. Our recent feasibility study and simulation of common two-qubit error sources shows that error rates of less than 1E-4 at clock speeds of 1 MHz for transport and quantum gates should be feasible.