Topological phases are not limited to electronic systems and can also exist in magnetic materials characterized by magnetic waves, known as magnons. While scientists have developed methods for producing and measuring magnon currents, they have yet to directly observe a magnon topological phase.
A magnon travels through a magnetic material by disturbing its magnetic order, similar to how a sound wave travels through the air. That order can be imagined as a collection of spinning tops sharing a particular rotation axis. The effect of the wave is to slightly tip the axes around which the tops are spinning.
A topological magnon phase is associated with channels that can carry a current of magnons along the edges of the sample. Researchers are hopeful that such edge channels can be utilized to carry information in future spintronics devices, analogous to how electric currents are used to transmit signals in electronic devices. However, before such technologies can be realized, scientists need to find a way to validate if a magnetic phase is topological or not.
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