Colloquium: Antiferromagnetic spintronics
CIC nanoGUNE Seminars
- Speaker
-
Tomas Jugnwirth, Academy of Sciences of the Czech Republic & University of Nottingham
- When
-
2018/05/14
13:00 - Place
- nanoGUNE seminar room, Tolosa Hiribidea 76, Donostia - San Sebastian
- Add to calendar
-
iCal
Louis Néel pointed out in his Nobel lecture that while interesting from
theoretical viewpoint, antiferromagnets did not seem to have any applications.
Indeed, the alternating directions of magnetic moments on individual atoms and
the resulting zero net magnetization make antiferromagnets hard to control by
tools common in ferromagnets. This has hindered both the research and utility
of these abundant magnetic materials. Recent studies have shown, however, that
relativistic quantum mechanics can provide staggered current induced fields
whose sign alternates within the magnetic unit cell of the antiferromagnet and
can be used to efficiently reorient the Néel vector. Combined electrical
writing and electrical readout have been experimentally demonstrated in thin-
film antiferromagnets CuMnAs or Mn2Au and a proof-of-concept USB device has
been realized showcasing binary and multi-level characteristics of memory
cells fabricated in these antiferromagnets. The absence of dipolar fields is
favorable for high density integration and makes the memory robust against
external magnetic field perturbations. The multi-level switching allows to
integrate memory with logic or neuromorphic functionalities within the bit
cell. Another unique merit of antiferromagnets is the ultra-fast, THz spin
dynamics which has allowed to demonstrate switching by electrical pulses whose
length has been scaled down to a picosecond. Despite recent progress,
antiferromagnetic spintronics is still at its infancy with the field’s full
potential yet to be explored. We will conclude the lecture by outlining the
rich symmetry and topology landscape that is now emerging by including
antiferromagnets in spintronics to stimulate a renewed basic and applied
research interest in these historically overlooked Néel’s magnets.
**Host** : J.M. Pitarke