In the realm of energy-efficient information technologies, spintronics has been a beacon of hope, promising devices that leverage the spin of electrons rather than their charge to process information. A team of researchers from the University of California, Berkeley, led by Professor Fanxian Pei, has recently made a significant stride in this field with their work on Janus altermagnets, published in the journal Nature Communications.
The researchers have proposed a novel approach to generate and control spin currents in two-dimensional (2D) altermagnetic semiconductors. This approach, termed the spin photovoltaic effect, allows for the predictable control of giant spin injection currents. Unlike other magnetic phases such as ferromagnetism and antiferromagnetism, altermagnetism offers unique advantages for spin current generation and control.
The team identified Janus Fe$_2$SSeO as a promising candidate for this effect. Janus altermagnetic semiconductors, distinct from parity-time (PT)-antiferromagnets, generate not only shift current but also a unique injection current with spin momentum locked in a specific direction under linearly polarized light. This mechanism is absent in PT-antiferromagnets, making Janus altermagnets a novel platform for spin current generation.
Through symmetry analysis and first-principles calculations, the researchers demonstrated that the monolayer Fe$_2$SSeO exhibits a polarization-dependent injection conductivity reaching approximately 1,200 μA/V²·ħ/2e. Moreover, the giant spin injection current can be effectively switched by rotating the magnetization direction and engineering strains. These findings highlight the potential of 2D altermagnets in spin photovoltaics and pave the way for innovative quantum devices.
For the energy sector, this research could lead to more energy-efficient data centers and computing technologies, which are increasingly significant as data consumption continues to grow. By enabling more efficient information processing, these technologies could help reduce the energy footprint of the digital economy.
In summary, the work of Pei and his team opens up new avenues for spintronics, offering a promising path towards energy-efficient information technologies. As the world seeks to reduce its carbon footprint, such advancements could play a crucial role in making our digital infrastructure more sustainable. The research was published in Nature Communications, a highly respected journal in the field of materials science and physics.
This article is based on research available at arXiv.