Single Review on past events

Working magnetic materials are an exciting field of fundamental physic research. In his Jour Fixe Talk, physicist Unai Atxitia introduced the audience into his research on such materials and future applications of these results.

The most basic technological application of magnetic material is the magnetic compass. The polarity of the Earth's magnetic fields is defined by the North Pole which direction can be detected with a compass and is used for navigation by humans or several animals, like migrating birds or bees. However, the polarity of the Earth´s is not fixed and can switch about every 1 million years, a process that takes several hundreds of years. Generally speaking, magnets are objects that produce magnetic fields and are able to switch their polarity.

Smaller magnets, that are able to switch their polarity way faster, are used in everyday technology. For example, magnets are used in medical research and therapy, such as Magnetic Resonance Imaging (MRI) or non-invasive cancer therapy. They are also very important for electric motors and digital data storage. In 2013, an estimated 4.4 zettabytes (10²¹ Byte) of data were stored globally. In 2020, 440 ZB of data storage is expected to be needed. For processing this enormous amount of data in a timely manner, new ways of storage and fast manipulation of information are necessary. However, current storage and data recording paradigms limit the speed of data storage and information processing to the nanosecond time scale.

Fundamental research on magnetism is therefore very important to develop new concepts which bypass the current limitations by exploiting alternative classes of materials and processes in magnetic memory devices. One of the main aspects is the speed of the switch of polarity. In his latest research, Unai Atxitia investigated the use of a femtosecond a laser pulse to switch the polarity at the vast speed of one picosecond, which is 0.000000000001 seconds, a thousand times faster than current technology.  The laser´s energy deposited as heat plays a crucial role  in this process.

Further basic research in this field may lead to Magnetic Memory Devices with higher density, faster speeds and lower cost.