Researchers at Tohoku University, in Japan, have developed the technology for nanosecond operation spintronics-based probabilistic bits (p-bits) for the first time. These probabilistic bits are based on the random telegraph noise (RTN) in nanoscale magnetic tunneling junctions (MTJ), which is stochastic in nature. For this technology to lead to viable probabilistic computers, it is necessary to develop stochastic MTJs with very short relaxation times in order to reduce the fluctuation timescale of the p-bit, increasing computing accuracy. In their recent work, published in Physical Review Letters, the authors demonstrate it is possible to increase the RTN speed, reaching relaxation times down to 8 ns in superparamagnetic in-plane easy-axis MTJs. This is a hundred times faster than previously reached.
“The developed MTJ is compatible with current semiconductor back-end-of-line processes and shows substantial promise for the future realization of high-performance probabilistic computers. Our theoretical framework of magnetization dynamics including entropy also has broad scientific implication, ultimately showing the potential of spintronics to contribute to debatable issues in statistical physics.”, said Shun Kanai, professor at Tohoku University and lead author of the study.