Whether it is the search for disease markers in a tiny drop of blood, the determination of the structure and dynamics of individual proteins in the body, or high-precision chemical analysis of surfaces. Current nuclear magnetic resonance technologies, such as medical MRI imaging or NMR spectroscopy, do not have the level of sensitivity that is needed for such investigations. Now, however, Professor Martin Plenio wants to bring quantum technology on board to utilise nuclear magnetic resonance on the micro- and nanoscale. For this innovative but risky research project, the German Research Foundation (DFG) has granted the theoretical physicist a Reinhart Koselleck Project and over 1.5 million euros for five years: This highly competitive research funding enables researchers with an outstanding scientific track record to pursue relevant questions with unclear prospects of success.
Nuclear magnetic resonance forms the basis of NMR spectroscopy, a standard method used in the research on atoms and molecules, and also of magnetic resonance imaging (MRI) used in medicine. These technologies use nuclear magnetic resonance to determine the structure of the molecular magnetic environment with high specificity. The devices currently used in research facilities or hospitals, however, are not very sensitive and require extremely strong magnetic fields. 'The relatively low sensitivity of today's NMR devices leads to an unfavourable signal-to-noise ratio and greatly limits their applicability to small samples,' explains Professor Martin Plenio, Director of the Institute of Theoretical Physics at Ulm University. In the course of the Reinhart Koselleck Project, Plenio wants to utilise quantum technology to overcome the limits of nuclear magnetic resonance. The ambition is to develop small, cost-efficient NMR devices that are easy to handle and can also be used in the general practitioner's practice, for instance.
Artificial nanodiamonds play a key role in this endeavour. In addition to improved control and detection methods, the researchers led by Plenio want to optimise diamond hybrid architectures in order to increase both their robustness to noise as well as their sensitivity to NMR signals. An important goal here is hyperpolarisation: In the colour centres of the artificial diamonds, the electron spin of the smallest particles can be directed in a controlled manner. Hyperpolarisation is achieved when the surrounding molecules are aligned accordingly so that all magnetic moments point in the same direction. In this state, the NMR signal would at best be amplified by a factor of 100,000, which means that such devices could achieve an unprecedented level of sensitivity. The amplified signal, however, would still be noisy and difficult to detect. The signal that is relevant for the researcher therefore needs to be separated from the noise with the help of signal processing methods. 'In recent years, research into the detection of gravitational waves has laid many foundations for the subtraction of noise, which we might be able to transfer to the Koselleck Project,' explains Martin Plenio, who joined Ulm University in 2009 with an Alexander von Humboldt Professorship. When it comes to signal processing and machine learning he relies on the expertise of computer scientists or engineers, who are going to be hired for the purpose of this project. Theorist Martin Plenio also works closely with experimental physicists, such as Ulm's expert for artificial diamonds Professor Fedor Jelezko. Jelezko's labs are conducting promising analytical work and computer simulations. This way, theoretical research benefits from the contact to experimental reality.
The Centre for Quantum and Biosciences (ZQB) is the ideal home for the Reinhart Koselleck Project: The natural scientists, molecular medicine experts and engineers will soon move into this unique research building that allows them to work door to door. 'The approval of the Reinhart Koselleck Project is also a first funding success for the ZQB,' Martin Plenio emphasises.
But why does the DFG rate the project as 'high-risk'? If all goes well, five years from now the researchers will have demonstrated that nanoscale NMR measurements are possible and start developing corresponding devices to market readiness. Nevertheless, it could also turn out that the application of high-resolution NMR cannot be realised on the micro- and nanoscale at this point in time.
In any case, even if the final goal does not get achieved: The researchers will be gaining useful insights for quantum sensor technology, which may lead to novel technologies. Professor Martin Plenio's project is also the first example for the great potential of the ZQB building: The Koselleck Project is possible only due to the close contact between researchers from physics, chemistry and medicine.
Reinhart Koselleck Project
Researchers with an outstanding scientific track record can apply to the DFG for a Reinhart Koselleck Project any time. A selection committee decides individually if and how much funding is approved (a maximum of 1.25 million euros plus so-called overheads). The relatively rarely approved funds for staff, equipment, etc. are given to highly innovative or, in a positive sense, higher-risk projects with a five-year duration. The project is named after the historian Reinhart Koselleck, who was one of the founders of modern social history and died in 2006. Ulm University's Professor Martin Bossert, Director of the Institute of Communications Engineering, was also selected for a Koselleck Project in 2009.