"We have essentially discovered the first magnetic photoconductor," said postdoctorate student Bálint Náfrádi.
The researchers have synthesised a ferromagnetic photovoltaic material whose magnetic properties can be modified, without changing the structure of electrons in the material's chemistry or crystal structure.
This new crystal structure combines the advantages of both ferromagnets, whose magnetic moments are aligned in a well-defined order, and photoconductors, where light illumination generates high density free conduction electrons.
With these two properties, a simple red LED is said to be enough to disrupt, or ‘melt’, the material's magnetic order and generate a high density of travelling electrons, which can be freely and continuously tuned by changing the light's intensity. The timescale for shifting the magnetic in this material is also very fast.
Although still experimental, these properties mean that the new material could potentially be used to build the next generation of memory storage systems, featuring higher capacities with low energy demands.
"This study provides the basis for the development of a new generation of magneto-optical data storage devices," added Náfrádi. "These would combine the advantages of magnetic storage – long-term stability, high data density, non-volatile operation and re-writability – with the speed of optical writing and reading."
