Trans-Scale Quantum Science Institute

Events

【6/24】Lecture by Dr. Qian Song(Department of Physics, MIT)

seminar

We are pleased to inform you that the online seminar will be held as follows.
Please see below for details. We look forward to your participation.

Title:P-wave Multiferroics
Speaker:Dr. Qian Song
     Department of Physics, MIT

Day:2025/6/24th(Tue)13:00~14:00  (JST)
Venue:Online
URL:https://u-tokyo-ac-jp.zoom.us/j/82431022494?pwd=4BiD7WPHlCWXtqPLeUhUsF6ecaNtaA.1

Altermagnets are a new class of magnetic materials possessing zero magnetization like antiferromagnets but exhibiting non-relativistic spin splitting of the electronic bands and anomalous Hall responses like ferromagnets. Recent studies have explored non-collinear non-centrosymmetric magnetic systems that exhibit odd-parity spin splitting with non-relativistic origin (p-wave magnets). Symmetry considerations suggest the possibility of coupling p-wave magnetism with ferroelectricity in polar chiral magnets, potentially allowing for novel mechanisms for electric-field control of p-wave magnetism.

In this talk, I will start by discussing our optical studies of spin spiral multiferroicity in van der Waals material NiI2 down to the two-dimensional limit. I will then focus on our recent work on electrical switching of p-wave magnetism in NiI2, and its connection to ferroelectricity and chirality. Lastly, I will conclude with an outlook for potential applications of spin-spiral multiferroics for information storage.

References

[1] Q. Song, et al. Electrical switching of a p-wave magnet. Nature 642, 64-70 (2025).

[2] Q. Song, et al. Evidence for a single layer van der Waals multiferroic. Nature 602, 601 (2022).