In a groundbreaking discovery, an international research team, spearheaded by TU Wien professor Andrej Pustogow, has demonstrated the transformative potential of pressure in actively changing magnetism within a crystal. The study, recently published in “Physical Review Letters,” unveils a novel method of continuously altering the type of magnetism in a material by applying pressure.
Traditionally, magnetism in materials is determined by the behavior of electrons. However, the ability to dynamically change the type of magnetism within a crystal has remained an elusive goal. This recent research has broken new ground by showcasing the capability to modulate magnetism in a crystal by adjusting magnetic interactions through the application of pressure.
Magnetism has captivated human interest for millennia, enabling numerous technological applications such as compasses, electric motors, and generators. While ferromagnetism has been extensively studied, recent research is delving into other forms of magnetism, especially those with potential applications in secure data storage and quantum computing platforms.
The study distinguishes between ferromagnetism, where electron spins align parallel to each other, and antiferromagnetism, where neighboring spins alternate between opposite directions. The research focuses on crystal structures with triangular, kagome, or honeycomb lattices, where geometrical frustration occurs due to the inability to achieve a completely antiparallel spin arrangement.
Geometrical frustration in crystal structures leads to randomly arranged spin pairs, opening possibilities for applications in quantum computers and data storage. The challenge lies in precisely controlling the symmetry of the crystal lattice and magnetic properties.
The researchers successfully altered the magnetic interactions within a crystal by applying uniaxial stress, deforming the crystal lattice from a kagome structure. The pressure-induced deformation changed the magnetic interactions between electrons, offering a method to actively control the material’s magnetic properties.
The team utilized mechanical pressure to reduce geometrical frustration in the crystal, resulting in a preferred magnetic direction. Professor Pustogow explains the concept, stating, “As sometimes in real life, stress reduces frustration because a decision is forced upon us and we don’t have to make it ourselves.” This approach increased the temperature of the magnetic phase transition by more than ten percent, showcasing the potential for precise control over material properties.
The researchers aim to further manipulate geometrical frustration by actively increasing it, ultimately eliminating antiferromagnetism and realizing a quantum spin liquid. Professor Pustogow concludes, “The possibility of actively controlling geometric frustration through uniaxial mechanical stress opens the door to undreamt-of manipulations of material properties ‘by pushing a button.'”
This groundbreaking research not only expands our understanding of magnetism but also paves the way for innovative applications in quantum technologies and material science.
