Tiny tornados for storing data
In today's technology-driven world, we need better computers for artificial intelligence tasks, more memory to store our data and more accurate sensors in future self-driving cars. “In my research, I design and develop functional nanodevices for magnetic field sensing and memory applications. I make use of tiny magnetic objects known as skyrmions and I study how they can be used for the next-generation energy-efficient devices,” says Sabri Koraltan, doctoral candidate at the Vienna Doctoral School in Physics, the Physics of Functional Materials research group and the Mathematics-Magnetism-Materials Research Platform.
Skyrmions: tiny local tornados
In your smart watch or in your car, for example, magnetic materials can store information after the power is gone, or can generate very fast signals to determine the position of a wheel. Magnets consist of millions or billions of tiny elementary magnets. “These magnetic moments, as we call them, can be imagined as tiny arrows pointing in a particular direction in space, usually aligned with an external magnetic field. But there are special materials, in which the magnetic moments do not align with the field, but form tiny local tornado-like objects: the skyrmions,” says the young physicist and explains, “We can move skyrmions by passing electric currents through our materials, or make them grow and shrink using external magnetic fields.”
"Which material has changed our society, Sabri Koraltan?"
Researchers at the University of Vienna are working on the materials of the future. We asked them which materials they think have had the greatest impact on humanity, and where the challenges lie in designing the materials of the future.
Sabri Koraltan: "Magnetic materials had a crucial impact on today’s technological advancement. Most of the data that we generate are stored on hard disks. How exactly? Hard discs contain magnetic material in which the microscopic elementary magnets are aligned in different directions. These different alignments encode for the bits "0" and "1". The materials used are iron and platinum. Now we use iron, cobalt and platinum and other heavy metals to develop the next generation of magnetic nanodevices."
"What are the biggest challenges in developing new materials?"
Sabri Koraltan: "One of the main challenges we have in researching new materials for a greener and more energy-efficient future is the miniaturisation problem. As we aim to fit more and more bits in a smaller and smaller area, we need to develop novel tools to fabricate these materials, but also new computational and experimental methods to investigate them."
Under extreme conditions
In the Physics of Functional Materials research group at the University of Vienna, Koraltan develops novel numerical tools to investigate magnetic systems: Simply put, they perform micro-magnetic simulations. “We design geometries in a computer program and investigate how the magnetic moments are arranged, and how they respond to external stimuli,” explains the physicist, whose supervisor Dieter Suess and mentor Claas Abert are leading experts in micromagnetic simulations.
Sensors for cars, computers or biomedical industry
Every year, the amount of data that we need to store grows exponentially. “By the year 2025, we will create 181 zetabyte of data. It is the equivalent of 181 trillion gigabytes,” the researcher points out. “Thus, we need to explore alternative storage concepts. When it comes to our sensors, we need to operate them with as little energy consumption as possible.”
By combining fundamental research and industrial applications, Koraltan and his colleagues develop sensors that are highly sensitive and accurate and can be used in our cars, computers or applications in biomedical industry. (red)
16 Vienna Doctoral Schools. Since 2020.
Since 2020, the Vienna Doctoral Schools provide excellent conditions including team supervision and various funding possibilities that enable the realisation of international competitive research. In the doctoral schools, doctoral candidates find an active and inspiring research environment, a vibrant doctoral community and many ways to connect with peers from home and abroad on a social and professional level.