Modern information technologies rely fundamentally on magnetic materials, with magnetic ordering playing a central role in data-storage and sensing technologies. At present, magnetization is typically controlled by electric currents or direct electronic excitation. While effective, these approaches generate substantial heat and are approaching limits in terms of speed and energy-efficiency. Identifying alternative ways to manipulate magnetic order therefore represents an important scientific and technological challenge.
HandShake seeks to explore a fundamentally different strategy based on controlling magnetic order through atomic motions. In crystalline solids, atoms vibrate collectively in well-defined patterns known as phonons. When these vibrations are circularly polarized, meaning that the atoms follow rotational trajectories, they can carry angular momentum. The central aim of HandShake is to explore whether such controlled lattice motions can create a magnetization and an accompanying magnetic field, directly interacting with and even potentially switching magnetic ordering.
The overall objective of HandShake is to determine whether circularly polarized lattice vibrations can be used as a reliable and efficient tool to influence magnetization on ultrafast timescales. To address this question, the project combines intense and highly tuneable mid- and far-infrared light pulses from a free-electron laser with synchronized ultrafast optical detection methods. This facilitates both the selective excitation of specific vibrational modes in condensed matter and the direct observation of how magnetic properties evolve within trillionths of a second.
By establishing whether and how lattice dynamics can steer magnetic order, HandShake aims to deepen our understanding of the coupling between structural motion and magnetism, and to lay the groundwork for alternative approaches to magnetic control.
