I was chairing a session on (coupled electron-phonon dynamics at the nanoscale)[] in the morning. The focus session “Electron, Exciton, and Heat dynamics at the Nanoscale” used … not to include “heat” at all, and we suggested the title/content modification to APS two years ago –It was quite satisfactory to see that there were enough talks this year to fill a full session.

A particular highlight of the session were the talks of (Prof. Brian Regan)[] and his (student, ???)[] from UCLA, who have developed a technique able to probe the metallicity and the structure of a nanoscale interface in operando using a TEM in a mode (unbeknown to me) named EBIC. They showed application of their methods to filament formations for ReRAM as well as Mott-Insulator -based selector devices. Few works would have examplified the intent of the session better than these 2.

Other highlights:

  1. (Alexander Kemper from NCSU)[] talked about his studies on time-resolved angle-resolved spectroscopy
  2. (Amy Liu from Georgewotn)[] spoke of the charge density waves present in 1H and 1T TaS2, a topic she has pioneered with Michelle Johannes and Mazin. Fun fact: (her talk)[] featured an heresy I have spoken
  3. (Feliciano Giustino of Oxford)[] gave a very clear and thorough talk on the topic of computing the electron and hole mobilities of silicon from first principles using Boltzmann transport equation. The short version (of his talk)[] is that it is horribly challenging to so with good accuracy, in particular for the hole mobilities. A longer version is that describing the valence band of silicon even with state-of-the-art methods such as GW with spin-orbit coupling and electron-phonon induced renormalization remains a daunting task for people interested in the effective mass. He suggested that the community should carefully look into benchmarking its electronic structure on effective masses of materials –a very interesting idea. It is not sure we will like what we find though, as the poor description of the hole dispersion might be orginating from the breakdown of the pseudopotential approximation.

Rant of the day: the right timer strategy at the March meeting Having chaired a session this morning, I am more convinced than ever that the right strategy to keep people on pace at the March meeting is to set the timer to 10 minutes (the duration of the talk), instead of 12 minutes (the timeslot allocated to speakers for talk + questions).