Theoretical physicists in Innsbruck have proposed a scalable quantum computer architecture. The new model, developed by Wolfgang Lechner, Philipp Hauke and Peter Zoller, overcomes fundamental limitations of programmability in current approaches that aim at solving real-world general optimization problems by exploiting quantum mechanics.
Within the last several years, considerable progress has been made in developing a quantum computer, which holds the promise of solving problems a lot more efficiently than a classical computer. Physicists are now able to realize the basic building blocks, the quantum bits (qubits) in a laboratory, control them and use them for simple computations.
For practical application, a particular class of quantum computers, the so-called adiabatic quantum computer, has recently generated a lot of interest among researchers and industry. It is designed to solve real-world optimization problems conventional computers are not able to tackle. All current approaches for adiabatic quantum computation face the same challenge: The problem is encoded in the interaction between qubits; to encode a generic problem, an all-to-all connectivity is necessary, but the locality of the physical quantum bits limits the available interactions.
“The programming language of these systems is the individual interaction between each physical qubit. The possible input is determined by the hardware. This means that all these approaches face a fundamental challenge when trying to build a fully programmable quantum computer,” explains Wolfgang Lechner from the Institute for Quantum Optics and Quantum Information (IQOQI) at the Austrian Academy of Sciences in Innsbruck.
Fully programmable quantum computer
Theoretical physicists Wolfang Lechner, Philipp Hauke and Peter Zoller have now proposed a completely new approach. The trio, working at the University of Innsbruck and the IQOQI, suggest overcoming the challenges by detaching the logical qubit from the physical implementation. Each physical qubit corresponds to one pair of logical qubits and can be tuned by local fields. These could be electrical fields when dealing with atoms and ions or magnetic fields in superconducting qubits. “Any generic optimization problem can be fully programmed via the fields,” explains co-author Philipp Hauke from the Institute for Theoretical Physics at the University of Innsbruck, Austria. “By using this approach we are not only avoiding the limitations posed by the hardware but we also make the technological implementation scalable.”
Because of the increased number of degrees of freedom, which could also lead to non-physical solutions, the physicists arrange the qubits in a way that four physical qubits interact locally. “In this way we guarantee that only physical solutions are possible,” explains Wolfgang Lechner. The solution of the problem is encoded redundantly in the qubits. “With this redundancy our model has also a high fault-tolerance,” says Lechner. The new architecture can be realized on various platforms ranging from superconducting circuits to ultracold gases in optical lattices.
“Our approach allows for the application of technologies that have not been suitable for adiabatic quantum optimization until now,” says the physicist. Lechner, Hauke and Zoller have introduced this new model in the journal Science Advances. The scientific community has also expressed great interest in the new model. Peter Zoller is convinced: “The step from mechanical calculators to fully programmable computers started the information technology age 80 years ago. Today we are approaching the age of quantum information.”
A patent for the new quantum computer architecture has been submitted this year. The scientists are financially supported by the Austrian Science Fund (FWF) and the European Research Council (ERC) among others.
Publication: A quantum annealing architecture with all-to-all connectivity from local interactions. W. Lechner, P. Hauke, P. Zoller. Sci. Adv. 1, e1500838 (2015). doi:10.1126/sciadv.1500838
Institute for Quantum Optics and Quantum Information
Austrian Academy of Sciences
Phone: +43 512 507 4788
University of Innsbruck
Phone: +43 512 507 32022
Mobile: +43 676 872532022
http://dx.doi.org/10.1126/sciadv.1500838 - A quantum annealing architecture with all-to-all connectivity from local interactions. W. Lechner, P. Hauke, P. Zoller. Science Advances 1, e1500838 (2015)
http://www.iqoqi.at - Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences
Dr. Christian Flatz | Universität Innsbruck
APEX takes a glimpse into the heart of darkness
25.05.2018 | Max-Planck-Institut für Radioastronomie
First chip-scale broadband optical system that can sense molecules in the mid-IR
24.05.2018 | Columbia University School of Engineering and Applied Science
The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.
Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
25.05.2018 | Event News
02.05.2018 | Event News
13.04.2018 | Event News
25.05.2018 | Event News
25.05.2018 | Machine Engineering
25.05.2018 | Life Sciences