An experimental setup using mirrors to direct and focus ultrashort light pulses onto a magnetic sample.Lancaster University
Scientists have uncovered a new way to control magnets using flashes of light lasting less than a trillionth of a second.
The approach triggers unusually large magnetic motion without direct contact or sustained energy input.
Led by researchers at Lancaster University, the international team showed that subtle electronic effects can greatly amplify how magnets respond to ultrafast light.
The findings deepen scientific understanding of magnetism at extreme speeds and could guide the design of faster, more efficient technologies.
Scientists say the discovery reveals a fundamental mechanism that could reshape how magnetic states are controlled in future devices.
Light-driven magnetic motion
The team studied how extremely short electromagnetic pulses affect magnetization inside solid materials.
These pulses briefly disturb the magnetic order, causing spins to tilt away from their original direction.
Researchers tested two closely related magnetic materials.
Each material shared similar properties but differed in the structure of its electronic orbitals. Orbitals describe how electrons move around an atomic nucleus.
After exposing the materials to ultrafast light, the team analyzed the resulting magnetic state.
They found a dramatic difference in how strongly each material responded.
In one case, interaction between orbital motion and electron spin amplified the effect.
The light pulse produced a spin deflection up to ten times larger than in the material lacking that interaction.
This result shows that orbital motion plays a key role in magnetic control. It also reveals a highly efficient pathway for steering magnetization using light alone.
Magnetism begins with electrons. As electrons orbit the nucleus and spin on their axis, each one acts like a tiny magnet, known as a spin. The collective behavior of these spins determines a material’s magnetic direction.
In solids, electrons interact with one another and with nearby atoms. These interactions lock spins into preferred orientations. They also define how easily external stimuli can move them.
Light can influence both electron orbitals and spins. When orbital motion strongly couples to spin, the response becomes much stronger.
The researchers showed that this coupling allows light to transfer angular momentum more efficiently.
This mechanism enables rapid magnetization steering on ultrafast timescales. With sufficient control, the magnetization can shift far from equilibrium.
In some cases, it can even reverse direction entirely.
Such control lies at the heart of magnetic data storage, where information is encoded as “0” or “1” based on magnetic orientation.
Implications for future devices
Magnetic materials remain central to modern technology. Data centers rely on them to store vast amounts of information.
Smartphones and computers use magnetic sensors for navigation and positioning.
Improving magnetic control could make these systems faster and more energy-efficient. Light-based techniques also reduce heat and power losses associated with electric currents.
Lead author Dr Rostislav Mikhaylovskiy highlighted the broader impact of the work.
“We believe that this exciting discovery will stimulate further studies of the mechanisms governing the efficient and rapid control of magnetization for future quantum technologies.”
Researchers plan to explore other materials with strong orbital-spin coupling.
They also aim to refine ultrafast optical methods for real-world applications.
The study shows that hidden electronic motion can unlock powerful new ways to manipulate magnets.
It brings scientists closer to controlling magnetic matter at the fastest possible speeds.
The study is published in the journal Physical Review Letters.
The Blueprint
