Career: Computer Simulations of Glassy and Athermal Systems

1
Career Computer Simulations of Glassy and
Athermal Systems
Corey OHern, Yale University, DMR-0448838
We use a combination of theoretical and
simulation methods to understand
out-of-equilibrium systems. Examples
include granular and glassy materials. Granular
materials, such as sand, are typically composed
of cm to mm rough grains. Granular media occur
frequently in nature and have important industrial
and technology applications, yet we still do not
have a fundamental understanding of how these
systems behave. We are particularly interested in
how grains pack to fill space and how mechanical
and structural properties of the packing depend
on the construction process and grain-grain
interactions. When systems are described as
glassy, it means that these materials flow only
on extremely long time scales. Thus, glasses
exist in an intermediate state between solids
that do not flow and liquids that flow easily
and quickly. These materials have very
important applications for example in the
plastics and polymer industries. Our recent work
has focused on using simple models such as the
figure-8 and Manhattan systems shown to the
right to explain the sluggish behavior and
predict the viscosity of model glassy systems.
Grains with purely repulsive interactions
Grains with attractive interactions
Manhattan model for glasses
figure-8 model for arrested dynamics
2
Career Computer Simulations of Glassy and
Athermal Systems
Corey OHern, Yale University, DMR-0448838
Education
Outreach

• Organized the 2nd New England Granular Materials
• Workshop and Focus Sessions on jamming for 05
• and 06 APS March Meetings
• Organized Boulder Summer School on Condensed
• Matter and Materials Physics, July 2006. School
• featured two public science lectures on soft
  matter
• attended by local Bolder community.
• As member of Graduate Writing Committee will
• develop curriculum to improve writing and oral
• presentation skills of graduate students.

• The people involved in this work include Ph.D.
• students Ning Xu (Mech. Eng., 2005), Prasanta
  Pal
• (Applied Physics, 2009), and Guo-Jie Gao (Mech.
  Eng.
• 2009) and many undergraduate students including
  Ajay
• Shalwala (Chem. Eng., 2005), Erik Brown (Physics,
  
• 2006), Chris Yerino (Physics, 2006) and Phillipa
• Thomson (Mech. Eng., 2006) for their senior
  thesis
• projects. Ian Rose (Physics, 2009) and Alexandra
  
• Witthoft (Physics, Mt. Holyoke College, 2009)
  worked
• with me during the summer 06 as a part of Yales
  
• Perspectives on Science program and a joint
  Yale-Mt.
• Holyoke Summer Undergraduate Research Program.
• A postdoc, Gregg Lois, also recently joined from
  UCSB.
• Developed new graduate course Numerical
  Simulations
• of Liquids that covers a host of simulation
  techniques for
• liquids and a module on granular materials
  simulations.

OHern group, Sept. 2006