Sound Waves Could Power the Next Generation of Spintronic Devices

The study, published in Physical Review B, could contribute to the development of strain-engineered technologies in which mechanical deformation controls magnetic or electronic properties.

Scientists have identified a new method to generate and control spin currents using sound waves, a development that could support energy-efficient computing, quantum technologies, and advanced communication systems. A research team from the Institute of Nano Science and Technology (INST), Mohali, an autonomous institute under the Department of Science and Technology (DST), has demonstrated how surface acoustic waves can be used to manipulate magnons, tiny magnetic excitations that carry spin information through materials. Their findings provide a fresh route for transmitting information without relying on the movement of electric charge, which is often accompanied by heat generation and energy loss.

Magnons Offer an Alternative to Conventional Electronics

Modern electronic devices depend on the flow of electrons to process and transfer information. As devices become smaller and more powerful, managing heat and reducing energy consumption have become major challenges. Researchers are therefore investigating spintronics, a field that uses the intrinsic spin of particles to carry information instead of electrical charge.

Magnons have attracted considerable attention in this area because they can transport spin information with significantly lower energy dissipation. These magnetic waves travel through materials as collective disturbances in their magnetic structure, making them promising candidates for future low-power technologies.

PhD scholar Shivam Sharma and his supervisor Prof. Abir De Sarkar explored how sound waves interact with magnons in a specially designed two-dimensional magnetic material. Earlier studies had examined the influence of surface acoustic waves on electrons and separately investigated the role of quantum geometric properties in magnon behaviour. The researchers recognized an unexplored connection between these areas and developed a theoretical framework to study it.

Tiny Material Distortions Create Controllable Spin Currents

The team built an analytical model involving an ultrathin graphene-like magnetic material placed on a piezoelectric substrate, a material capable of generating electric effects when subjected to mechanical pressure. They then examined how surface acoustic waves travelling across the structure affect magnon motion.

Their analysis revealed that the travelling sound waves create extremely small distortions within the material. These distortions behave like effective forces, known as pseudogauge fields, which alter the movement of magnons. As a result, spin currents can be generated and controlled through sound waves alone.

This mechanism introduces a completely different way of manipulating spin information inside two-dimensional magnetic materials. Since the process relies on sound-induced effects rather than conventional electrical currents, it opens possibilities for devices that consume much less power.

The study, published in Physical Review B, could contribute to the development of strain-engineered technologies in which mechanical deformation controls magnetic or electronic properties. Such approaches are expected to play an important role in future computing systems, where improving performance while lowering energy consumption remains a key challenge.