Petrosyan and co-authors have proposed the world’s first quantum spin transistor. The discovery is an important leap forward towards building quantum computers and networks by finding technological solutions to some of the central challenges.
The spin ½ particle, such as an electron, is a paradigmatic qubit – the quantum analog of a classical bit – in the quantum computer that can potentially solve many currently intractable problems. In a classical computer, the transistor plays the central role in executing logic operations. In a quantum computer or a network based on the chain of spins, the equivalent device was lacking. Now, Dr. David Petrosyan with a group of collaborators from Aarhus University and Heriot-Watt University (UK) have demonstrated theoretically how such a quantum spin (or qubit) transistor can be built. The basic idea is simple: The quantum state of the control qubit determines whether or not the gate is open or closed for the transfer of the target qubit between the input and output ports of the transistor. A proof-of-concept realization of the device can be done with just a few cold, trapped atoms, but the idea is generally applicable to various other implementations of spin chains.
“My stay at AIAS was very productive and rewarding, both scientifically and personally. The present result is an excellent example of a productive and mutually beneficial collaboration. Dr. Nikolaj T. Zinner and his group at the Department of Physics and Astronomy of the AU have recently developed a sophisticated formalism to calculate and engineer spin chains with cold atoms, while I specialize in quantum optics and quantum computation. The synergy of our expertise led to the results now published in three scientific papers, culminating with the present Nature publication on the realization of the quantum spin transistor”,– says Petrosyan – “I am very happy about this collaboration which of course will continue and hopefully yield more fascinating results and scientific publications.”
The significant results were published this week in the article ‘Quantum spin transistor with a Heisenberg spin chain' in the prestigious journal Nature Communications 7, 13070 (2016) and part of the results of Petrosyan’s fellowship at AIAS. With these results, David Petrosyan and the research group lead by Nikolaj T. Zinner based at Aarhus University have paved a new way to transfer quantum information and implement quantum logic in an atomic system that can function as a register of the quantum computer.
Read the article ‘Perfekt overførsel i kvanteland’ at: http://scitech.au.dk/roemer/3-2016/perfekt-overfoersel-i-kvanteland/ (in Danish only)
Read the scientific publication ‘Quantum spin transistor with a Heisenberg spin chain’ on Nature Communications website: http://www.nature.com/articles/ncomms13070
Dr. David Petrosyan, AIAS Former Fellow, Principal Researcher
Institute of Electronic Structure & Laser (IESL)
Foundation for Research & Technology-Hellas (FORTH)