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]

Fernandez-Serra

Sept. 26

Matthew Sfeir

Center for functional nanomaterials, BNL



Fernandez-Serra

Oct. 3

Richard Averitt

UCSD




Liu

Oct. 10

Mike Williams

MIT



Piacquadio

Oct. 17


Giuseppe Mussardo
SISSA


Rastelli

Oct. 24

Jon Simon

University of Chicago



Metcalf

Oct.31

Joanna Kiryluk

Stony Brook University



Nov. 7

Gordon Cates
University of Virginia





Kumar

Nov. 14

Pedro Vieira

Perimeter Institute and ICTP-SAIFR



Rastelli

Nov. 21

Scott Dodelson

University of Chicago



Perna

Nov. 28

Neelima Sehgal

Stony Brook University



Dec. 5

Marivi Fernandez-Serra

Stony Brook University