Taming the power consumption of computers with a new material “spin glass”.

A newly discovered material and its intriguing properties could pave the way for more efficient computing.

In a new study, a team of European physicists has discovered a distinctive collective behavior in the atoms of a material called manganese-doped germanium telluride that occurs at very low temperatures and gives rise to fascinating properties.

These findings are not only interesting from a basic research point of view, but hold the potential for a significant breakthrough in information technology, promising to make computations less energy-intensive by orders of magnitude.

Reign in power consumption

Computers and information technology have transformed society in recent decades, entering almost every aspect of industry, technology, science and our daily lives. However, the inexorable growth in performance and capabilities of computers has led to a corresponding increase in energy consumption, accompanied by the need to manage the heat generated by more powerful computers.

A possible way to solve these problems could be new, more energy-efficient materials, which could lead to a significant reduction in the power consumption of computers.

One such material is germanium telluride, which was investigated in a recent study published in Nature Communications carried out by an international team of researchers led by Hugo Dill of the Swiss Federal Institute of Technology in Lausanne, Günther Springholz of the Johannes Kepler University of Linz and Jan Minnar of the University of West Bohemia.

Through a process called “doping,” the team introduced small amounts of manganese atoms into the crystal lattice of germanium telluride, resulting in manganese-doped germanium telluride, which at low enough temperatures becomes ferrimagnetic and, on further cooling, becomes which is known as spin glass.

The rotating glass phase

Ferrimagnetism is a specific form of magnetism in which the spin or spin of some of the material’s atoms point in one direction while the rest point in the opposite direction. This behavior differs from the more familiar ferromagnetic behavior seen in materials such as iron, where all the spins are oriented along the same line, creating a magnetic field.

At super-low temperatures, below approximately -230 degrees Celsius, germanium telluride enters the spin glass phase, in which the spins of all its atoms become random.

Under an applied magnetic field or electric current, spin glass materials react differently than more conventional materials, which can be of great use in computing because the directions of atomic spins can be used to encode information that the computer can manipulate.

The authors of the study found that they could change the direction of the magnetic field generated by manganese-doped germanium telluride by passing a current through it. The most important part is that the current required to make the change is about six orders of magnitude less than what is typically required, which can significantly reduce power consumption when performing spin-manipulation-based calculations in this material.

“This is possible because the system forms a correlated spin glass, where the local magnetic moments are in a glassy state, much like atoms in an old-fashioned window,” Dill said in a press release. “If one spin is forced to change its orientation, that information will travel as a wave through the sample and cause the other magnetic moments to switch as well.”

Spin glass calculations

In its spin-glassy state, manganese-doped germanium telluride becomes very sensitive to an applied electric current, which offers the possibility of the magnetic field behaving as a bit of information corresponding to a 1 or a 0 (just like a normal computer bit). If very little energy is required to change the value of a bit, then the energy required to execute an entire algorithm will also be correspondingly low.

“For technological applications, this increase in switching efficiency is of course very interesting,” Dill explained. “This could eventually lead to computers that need less than a millionth of the power currently required to switch a bit.”

“However, as a physicist, what really intrigues me is collective behavior. We are now planning spatially and temporally resolved experiments to track how these excitations propagate and how we can control them.

Reference: Juraj Krempaský ​​et al, Efficient magnetic switching in a correlated spin glass, Nature Communications (2023). DOI: 10.1038/s41467-023-41718-4

Feature Image Credit: Kristina0000 on Pixabay

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