The European Research Council (ERC) has awarded a Starting Grant of nearly 1.5 million euros to Konstanz physicist Richard Schlitz for his project: "Magnons and Antimagnons: Engineering Dissipation to Explore the Limits of Nonequilibrium Magnetism" (MERLIN).

Numerous modern technologies, including hard disk drives, utilize spintronics to optimize their performance. In spintronics, the intrinsic angular momentum of an electron (the spin) is used to store, process and transmit data. While today's technologies are based on individual spins, the use of entire spin waves is expected to play a key role in the technologies of the future. These spin excitations, known as magnons, arise from the collective motion of hundreds of sextillions of spins. Physicist Richard Schlitz from the University of Konstanz conducts research on precisely these magnons. His project, "Magnons and Antimagnons: Engineering Dissipation to Explore the Limits of Nonequilibrium Magnetism" – or MERLIN for short – is now being funded by the European Research Council (ERC) through a Starting Grant. The grant amounts to just under 1.5 million euros over a five-year funding period starting in January 2027.

Aligning electrons with precision
A compass needle always points north. Unerringly. No matter how many times you spin around, it always aligns itself precisely with the Earth's magnetic field, reliably showing us the way. But when an artificial magnetic field is switched on, the needle is thrown off course and points in the wrong direction. When the field is switched off again, the needle returns to its original position. Physicists observe a similar phenomenon in electrons. Electrons not only carry a fixed charge, but also possess a magnetic moment due to their spin, which can point either up or down. The presence of a magnetic field makes one of these two orientations favourable, similar to the way the Earth's magnetic field aligns a compass needle toward the north.
Together with his team, Richard Schlitz aims to develop an alternative method for controlling electron spins. In his research project, he uses an experimental setup in which a crystal is coated with an ultra-thin layer of a magnetic insulator made of yttrium iron garnet. A further, very thin film of platinum is applied to this layer. "In platinum, we can sort the electrons specifically according to their orientation. When a current is applied, the electrons with spin-up orientation migrate towards the interface with the yttrium iron garnet, whereas spin-down electrons move towards the surface, where there is 'nothing'," explains Schlitz. "This forced sorting creates an imbalance in the system, which allows us to influence the relaxation of the electron spins in the yttrium iron garnet – that is, the return to their original state."
To this end, the physicist harnesses the interaction at the interface between the two layers. Under certain conditions, the magnetization can even reverse and point 'downward', opposite to the applied magnetic field, as though a compass needle suddenly pointed south rather than north. "What makes this new state particularly remarkable is that the excited system remains trapped in an energetically unfavourable configuration instead of relaxing back to the equilibrium state imposed by the magnetic field", he says.

Finding the button
What sounds, at first glance, like a simple push of a button and a predictable process is, in reality, still largely uncharted territory. "Our aim is to understand the properties of this novel state and control it precisely. So far, all we know is that it is possible to reach it. The precise mechanism is something we will need to uncover gradually, step by step", says Schlitz.

A deeper understanding of this phenomenon could bring significant benefits. Much like a compass needle, the electron spins would naturally prefer to return to their original orientation, but the excitation prevents them from doing so. They are effectively held in a state of tension. "The system seeks to dissipate energy in the form of magnons. In the future, we can potentially harness these magnons through their controlled manipulation and coupling to the environment, much as analogous effects are already used to great technological advantage in laser systems", explains the physicist.
This is all fundamental research, but the findings of the MERLIN project could eventually be applied in fields including communications technology and quantum computing. One possible application is the development of highly integrated microwave components for wireless communication technologies, which could be significantly more energy-efficient and therefore more sustainable than current technologies. "Still very much a vision for the future, but equally intriguing, is the prospect of using magnons to connect qubits in quantum computers", says Schlitz, offering a glimpse of another potential long-term application.

About the ERC Starting Grant
Every year, the ERC awards Starting Grants to promising early-career researchers. The aim is to give them the opportunity to set up and expand their own research teams and to move forward research projects with high innovation potential.
Key facts:

• Richard Schlitz has been awarded an ERC Starting Grant worth up to 1.5 million euros.
• The MERLIN project starts in January 2027 to investigate how magnons can be specifically influenced and harnessed through their interaction with electron spins in a non-equilibrium state.
• Dr Richard Schlitz is a physicist at the University of Konstanz and a member of Professor Sebastian Gönnenwein’s ‘Modern Material Science’ research team.