Manipulation of quantum many-body effects

Smaller yet faster?

With a spin that remembers

The Puzzle is solved

A pressing challenge facing information technology is the simultaneous improvement of electronic devices' processing speed and energy efficiency. Every time one switches on a computer or cellphone, electron charges begin their journey through microprocessors comprising millions of tiny switches, known as transistors.  The transistors decide whether electrons can pass or not, thereby communicating using "0" or "1". Over the decades, we have seen the electronic components shrinking in size at an incredibly rapid pace. Yet, this ever-growing trend is approaching its serious physical limit of energy consumption and heat dissipation, calling for new-concept memory and processing devices.

 

Spintronics is among the top emerging fields for non-volatile logic and memory devices, offering exciting alternatives to conventional electronics by encoding information into the spins of electrons instead of their charges.  The spin – a quantum mechanical property of electrons – behaves as little compass needles that can point up, down, or somewhere in between. Even without moving around inside a material, spins can store and process information via its discrete energy states, creating a whole new era of microprocessors. Traditionally focused on ferromagnets, spintronics research is now evolving towards antiferromagnetic materials. The negligible net magnetization of antiferromagnets makes them robust against stray fields, plus their resonance frequency lies in the range of THz, enabling ultrafast writing speed. However, the tiny response of antiferromagnetic materials to external fields represents a major obstacle for their practical applications. We recently discovered unusually large room-temperature anomalous transport effects in antiferromagnetic topological materials, a significant step forward in transferring spintronics concepts to real-life electronic components that are smaller, faster, and more energy efficient.

 

The following publications tell the in-depth story about how we manipulate the spin dynamics and spin transport of antiferromagnets for next-generation information technologies. Please feel free to check them out.

[1] M.-T. Suzuki et al., Phys. Rev. B 95, 094406 (2017).

[2] K. Kuroda, T. Tomita et al., Nat. Mater. 16, 1090 (2017).

[3] S. Nakatsuji, N. Kiyohara, and T. Higo, Nature 527, 212 (2015).

[4] N. Kiyohara, T. Tomita, and S. Nakatsuji, Phys. Rev. Applied 5, 064009 (2016).

[5] M. Ikhlas, T. Tomita et al., Nat. Phys. 13, 1085 (2017).

[6] T. Higo et al., Nat. Photon. 12, 73 (2018).

[7] T. Higo et al., Appl. Phys. Lett. 113, 202402 (2018). “Featured articles”

[8] D. Qu et al., Phys. Rev. Mater. 12, 73 (2018). “Editor’s suggestion”

[9] H. Tsai, T. Higo et al., Nature 580, 608 (2020).

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