Physics and Astronomy Colloquia, Academic Year 2017-2018

Colloquium committee: Leonardo Rastelli (Chair),  Marivi Fernandez-Serra, Eden Figueroa, Krishna Kumar, Mengkun Liu, Rosalba Perna, and Giacinto Piacquadio

Coffee & Tea served at 3:45 pm.

Talk begins at 4:15 pm.

Location: Harriman 137 (bottom of square C4 on the campus map)

Movies:  To watch the recorded movies, please  read the instructions here.

Fall 2017 colloquia

Sept. 12

Chair Colloquium

Chair’s Colloquium

   [recorded movies] on Firefox-ESR or VLC / rtsp://.

Sept. 19

Philip B. Allen

Stony Brook University

Electrons and Phonons in Solids
Electrons and phonons are the “quasiparticles” that determine the behavior of crystalline solids.  Quasiparticles are excitations with analogs to free particles.  Electrons in crystals, for example, have the same charge as free electrons, but altered mass.  They are accelerated by electric fields, obey Fermi statistics, and have hybrid particle/wave features like free electrons.  But they are also very different from free electrons.  In pure semiconductors, they disappear at low temperatures, emerging as electron-hole pairs, analogous to electron-positron pairs.  In metals at low temperature, they are constrained by a sharp Fermi surface, form Cooper pairs, and carry supercurrents.  Phonons are vibrational-wave particles that cannot be freed from their crystal host.  They are a lot like photons in vacuum, but more complicated.  We are still learning how to think about quasiparticles in crystals.  We want to understand how they evolve in time, temperature, and as their interaction strength varies.  The incredible diversity of crystalline matter gives us new surprises, challenges, and opportunities to deepen our understanding.

  [recorded movies]


Sept. 26

Matthew Sfeir

Center for functional nanomaterials, BNL


Oct. 3

Richard Averitt



Oct. 10

Mike Williams



Oct. 17

Giuseppe Mussardo


Oct. 24

Jon Simon

University of Chicago



Joanna Kiryluk

Stony Brook University

Nov. 7

Gordon Cates
University of Virginia


Nov. 14

Pedro Vieira

Perimeter Institute and ICTP-SAIFR


Nov. 21

Scott Dodelson

University of Chicago


Nov. 28

Neelima Sehgal

Stony Brook University

Dec. 5

Marivi Fernandez-Serra

Stony Brook University