Researchers at the University of the Basque Country propose a simple and economic qbit structure

The piece, entitled, “Optimal Control of Quantum Rings by Terahertz Laser Pulses” (1), proposes new annular structures (quantum rings) to define a qbit, i.e. the unit of information of quantum computers.. The work has been undertaken in collaboration with the Freie-Universität of Berlin and the research team there under university teacher, Eberhard K.U. Gross.

Unlike the binary bit of current computers which only has two possible states – 0 or 1 – the unit of measurement of quantic computers is the qbit which uses a much more complex logic involving multiple states, enabling the much more efficient processing of information. There are many proposed applications for the qbit, some based on quantic points embedded in matrixes, others on magnetic molecules, others on cold atoms, and so on. The UPV/EHU researchers propose a new system based on the interaction of laser light with a metallic structure in the form of a ring and which has been written on lithographically. The advantages of the system are its simplicity and its economy, given that its quantic state can be precisely controlled with light and the technique can be integrated into current electronic structures. Ángel Rubio and his team are currently working on a combination of a number of these structures so that they may interact and operations can be carried out.

This is the fourth research article published by Ángel Rubio in “Physical Review Letters” within the space of a year.

Ángel Rubio is lecturer in the Physics of Condensed Matter at the Faculty of Chemical Sciences at the UPV/EHU, a member of the Donostia Physics Center and an associate of the CSIC-UPV/EHU Physics of Materials Mixed Centre. His research activity is internationally recognised and he has received many awards, notable amongst which are the Award from the Sociedad Española de Física for young researchers (1992); the Friedrich Wilhelm Bessel research prize from the Humboldt Foundation (2005) and the DuPont Award for Science (2006).

(1) E. Räsänen, A. Castro, J. Werschnik, A. Rubio, and E. K. U. Gross Optimal Laser-Control of Quantum Rings, (Physical Review Letters (Vol.98, No.15).