Biological self-assembly of nanodiamond arrays have been proposed and experimentally implemented for the first time by a team of researchers around Prof. Martin Plenio at Ulm University, Germany.

It is a relevant breakthrough on the path towards quantum computers, since the use of tiny diamonds with a nitrogen atom at their core is one of the most promising ways to capture, generate and manipulate photons for this application. But it is extremely difficult to arrange those nano building blocks, just a few atoms wide, next to each other so that the quantum information they store can be accessed and processed, which is possible by the means of electric or magnetic fields.

The scientists around Prof. Martin Plenio, a world-renowned quantum physicist in his field and member of the Center for Integrated Quantum Science and Technology in Ulm, had the plan to bind nanodiamonds together by using biological molecules such as DNA and protein which are programmed to form suitable structures, at the required nanometer scale. The technique, called DNA origami, is used by biologists to create complex structures on nanoscales.

To implement this approach, the researchers coated nanodiamonds with a genetically modified protein called SP1. The protein bonds with other proteins on nanodiamonds, forming them into a hexagonal array, a process that was experimentally demonstrated to work as expected. It is a promising first step towards larger arrays needed for quantum computing, says Andreas Albrecht from Ulm University, who drafted the paper:

"We believe that the combination of nanodiamonds with biological systems provides a promising approach towards scalability overcoming the limitations of current attempts and offering a high level of control in both structure formation and qubit addressing."

The future looks bright for this field of research and the involved scientists. The research-team "Diamond Quantum Devices and Biology", with Prof. Plenio and two other scientists, just received the EUR 10 million ($13 mio) Synergy Grant, given to excellent researchers by the European Research Council, which will help substantially to "engage in really exciting, high-risk research" , said Plenio. Ulm University aims to become the worlds leading center of excellence in the field of Quantum Microscopy. Incidentally, the "Science City Ulm" in Southern Germany, Albert Einstein's birthplace, also hosts world leading companies that make synthetic diamond micro-technology (GMD), Atomic Force Microscopes for nanotechnology research and industry (WITec), and the worldwide leader in VCSEL technology, optical semiconductor chips needed for various high-tech applications, for example the fastest-possible fiberoptics as used in datacenters and supercomputers (U-L-M Photonics).

Paper: arxiv.org/abs/1301.1871: Self-Assembling Hybrid Diamond-Biological Quantum Devices