Graphite: the mother of all semimetals or the father of spintronics?

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Graphite: the father of all semimetals?
2023. 06. 02. 10:15
BME building F, seminar room of the Dept. of Theoretical Physics
Ferenc Simon (BME)
Graphite has been known to mankind since ancient times and has been intensively studied for more than 80 years. It is also the archetype of semimetals (metals with a small Fermi surface) and the mother compound of graphene and other two-dimensional van der Waals heterostructures. Albeit we have a vast knowledge about graphite, it turns out that its spin-relaxation properties are poorly understood and a recent revision of the system [1] yielded the surprisingly long 100 ns spin-lifetime in this material. This is an order of magnitude longer than the world-record holding bilayer graphene. It turns out that previous spin-relaxation studies were in fact not interpreted with the correct description and also that graphite has a hitherto unexplored symmetry which inevitably leads to this long spin-relaxation time. We speculate that this enables bulk graphite to become a viable candidate for using the electron spins as information carrier units in future spintronics devices.
[1]: B. G. Márkus et al. "Ultralong 100 ns spin relaxation time in graphite at room temperature", Nat. Comm. 14, 2831 (2023)