The generation, transmission and detection of magnons in graphene/2D magnet heterostructures

Spin waves, also known as magnons, are low-energy collective excitations of a magnetic system. The generation and control of magnons offer an alternative and potentially low-energy pathway of transmitting quantum information. Magnons are charge neutral and therefore more difficult to detect. Following previous studies [1][2], here we present an electric emission/detection scheme that allows the studies of magnons in a van der Waals magnet through the use of graphene quantum Hall edge states. We make graphene/2D magnet heterostructures and launch and detect magnons through non-local transport measurements in different regions of the device connected by the 2D magnet sheet only. Magnon transmission through the 2D magnet is observed. We analyze the dc bias, temperature, power and magnetic field dependence of the non-local signal to understand this process, which involves the emission of magnons in graphene, transmission through the graphene/magnet interface, and the detection in graphene again. This method can potentially be used to study the ground state magnetism and excitations of a large number of 2D magnets.

References:

[1] Wei et al, Electrical generation and detection of spin waves in a quantum Hall ferromagnet. Science, 2018, 362(6411), 229-233.

[2] Fu, et al, Gapless spin wave transport through a quantum canted antiferromagnet. Physical Review X, 2021, 11(2), 021012.