APS March Meeting 2022, Day 1

My first impressions of this year's March Meeting are a bit limited, since I flew today and didn't make it to the convention center until around 4pm.  Still, a few thoughts:

• Population density at the meeting does seem lower than 2019, though that could partly be because the convention center is enormous.  Attendance also seems to skew younger this year.
• It was interesting attending a contributed session, with a mix of in-person speakers and the session chair playing pre-recorded presentations from those who could not or chose not to be present.  It seems to work ok, though the lack of Q&A for the recorded talks takes some getting used to.  In asking around, I get the impression that the full live streaming interactive Q&A approach from last year's virtual meeting was very expensive to implement, and that's one reason why the method this year is different (with live streaming only for invited talks).
• While I was getting my bearings, I popped into a session about spin transport by electrons and magnons.  I saw a talk where an interesting "spin diode" effect takes place in a thin film multilayer structure consisting of (from one side to the other) permalloy/gold/platinum/cobalt.  Driving the permalloy layer into ferromagnetic resonance can effectively pump spin into the gold and so forth, and in that direction spin current flows and is absorbed in the cobalt.  However, if one instead drives the cobalt layer to try to push a spin current the other way, the permalloy does not act like a "sink".  This can be modeled and the directionality makes sense.
• I saw a second talk that somewhat similar in spirit, in which magnons are launched into an insulating magnet using the spin Hall effect in a Pt wire, and then detected by another Pt wire via the inverse spin Hall effect.  By placing a NiFe pad between the Pt wires, it is possible to make it so that magnons transport more easily from one Pt wire to the other than vice versa.  This work is described here.
• Then I went to the APS special session about Ukraine.  I expected this to be largely about how to help displaced scholars and scientists, but it was more complex, and most of the time was a listening session for the APS president and the CEO.  The APS statements about the Russian invasion of Ukraine are here.  There are many issues.  For example, 200+ rectors of top Russian universities and institutes signed an open letter supporting the war. Should the APS still allow those places to have journal access? Faculty members there to have society membership and privileges? What is mandated as a result of sanctions?  There are many Ukrainian and Russian and Belarusian physicists in the APS, and feelings are intense.  On an historical note, the question was raised about what if anything the APS did in regard to German physicists and institutions (like the German Physical Society and the Kaiser Wilhelm Institutes) when Germany invaded Poland in 1939 - can any readers point to a record of what the APS actually did?  I spent a while googling and could find nothing.

It is good to see folks face to face, even if attendance is down.  It's been a long time.