The spin-flop transition in the quasi-two-dimensional antiferromagnet MnPS₃ detected via thermally generated magnon transport

Antiferromagnetic materials (AFM) have gained great interest for information storage and as a medium for spin currents in spintronic devices because they do not possess stray fields, are robust against magnetic perturbations, and have ultra-fast magnetic dynamics. Characterizing and probing magnetic transitions in (quasi) 2-dimensional magnetic van der Waals materials is crucial to understand magnetism at a low dimensional limit; for example by characterizing the spin-flop (SF) transition in uniaxial AFM. We present the detection of the spin-flop transition in the AFM van der Waals material MnPS₃ via thermally generated nonlocal magnon transport using permalloy detector strips [1]. The inverse anomalous spin Hall effect has the unique power to detect an out-of-plane (OOP) spin accumulation which enables us to detect magnons with an OOP polarization; in contrast to Pt which only possesses the spin Hall effect and is only sensitive to an in-plane spin polarization [2]. Our measurements show the detection of magnons generated by the spin Seebeck effect before and after the SF transition where the signal reversal of the magnon spin accumulation agrees with the OOP spin polarization carried by magnon modes before and after the SF transition [1].

[1] F.Feringa, J.M. Vink and B.J. van Wees, https://arxiv.org/abs/2210.01418 (2022), submitted to PRL

[2] K. S. Das, J. Liu, B. J. van Wees, and I. J. Vera-Marun, Nano Letters 18, 5633 (2018).