EPJ Quantum Technol. (2017) 4: 3
https://doi.org/10.1140/epjqt/s40507-017-0056-x

Research

Spatial non-adiabatic passage using geometric phases

¹ Quantum Systems Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, 904-0495, Japan
² Department of Physics, University College Cork, Cork, Ireland
³ Department of Physics, Shanghai University, Shanghai, 200444, China

^* e-mail: albert.benseny-cases@oist.jp

Received: 8 November 2016
Accepted: 15 March 2017
Published online: 28 March 2017

Abstract

Quantum technologies based on adiabatic techniques can be highly effective, but often at the cost of being very slow. Here we introduce a set of experimentally realistic, non-adiabatic protocols for spatial state preparation, which yield the same fidelity as their adiabatic counterparts, but on fast timescales. In particular, we consider a charged particle in a system of three tunnel-coupled quantum wells, where the presence of a magnetic field can induce a geometric phase during the tunnelling processes. We show that this leads to the appearance of complex tunnelling amplitudes and allows for the implementation of spatial non-adiabatic passage. We demonstrate the ability of such a system to transport a particle between two different wells and to generate a delocalised superposition between the three traps with high fidelity in short times.