Replacing ferromagnets (FMs) in spintronics devices by antiferromagnets (AFMs) has attracted attention because of the expectation for realizing ultrafast and ultralow power devices [1,2]. Recent intensive studies on AFMs with macroscopically broken time reversal symmetry has solved the difficulty controlling and detecting the antiferromagnetic order with a vanishingly small magnetization [2,3]. A chiral AFM Mn₃Sn is the most studied antiferromagnetic material possessing such a lower symmetry. The practical integration of AFMs into device architectures is becoming realistic after the recent experimental confirmation of the electrical control of the antiferromagnetic order via spin orbit torque [4] and its detection through the tunneling magnetoresistance in this material [5]. Given the development of ferromagnetic spintronics, the local manipulation of the magnetic properties by interlayer coupling such as the exchange bias effect is essential for developing antiferromagnetic spintronics. For better compatibility with existing Si-based devices, this manipulation of antiferromagnetic order should be realized in polycrystalline thin films. In this presentation, we report the exchange bias effect observed at the interface between polycrystalline Mn₃Sn and collinear AFM MnN films on an amorphous substrate.
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