User:Askeys

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Personal Information:

Name: Aaron Keys
Affiliation: The Glotzer Group @ The University of Michigan (2004-current)
email: askeys at umich dot edu

Education:

• September’04–Present: Progress towards Ph.D. in Chemical Engineering at the University of Michigan.
• Spetember’00-May’04: B.S.E. in Chemical Engineering at the University of Michigan.

Awards and Honors:

• GAAN Fellowship (2005)
• Summa Cum Laude (2004)
• Omega Chi Epsilon (2002-2004)
• James B. Angell Scholar (2002)
• William J. Branstrom Freshman Prize (2001)

Selected Publications:

1. A. Haji-Akbari, M.E. Engel, A.S. Keys, X.Y. Zheng, R.G Petchek, P.P. Palffy-Muhoray, S.C. Glotzer, "Disordered, quasicrystalline, and crystalline phases of densely packed tetrahedra," Nature 462, 773-777 (2009) [1]
2. S.C Glotzer and A.S. Keys, "A tale of two tilings," Nature 454, 420-421 (2008) [2]
3. A.S. Keys and S.C. Glotzer, “How Do Quasicrystals Grow?” Phys. Rev. Lett., Phys. Rev. Lett. 99, 235503 (2007) [3].
4. A.S. Keys, A.R. Abate, S.C. Glotzer, and D.J. Durian, “Measurement of growing dynamical length scales and prediction of the jamming transition in a granular material,” Nature Physics 3, 260–264 (2007) [4].
5. C.R. Iacovella, A.S. Keys, M.A. Horsch, and S.C. Glotzer, “Icosahedral packing of polymer-tethered nanospheres and stabilization of the gyroid phase,” Phys. Rev. E 75, 040801(R) (2007) [5].
6. Z. Zhang, A.S. Keys, T Chen, S.C. Glotzer, “Self-Assembly of Patchy Particles into Diamond Structures through Molecular Mimicry,” Langmuir. 21(25):11547-51 (2005) [6].

Featured Press:

1. Cover image on The National Academies Press Report: Physics 2010 [7]
2. "Quasicrystal Mystery Unraveled With Computer Simulation" Science Daily (Mar. 11, 2008) [8]
3. Research Highlights, Nature 451, 110-111 (10 January 2008) [9]
4. P.J. Steinhardt, "How Does Your Quasicrystal Grow?" Nature 452, 43-44 (2008) [10]
5. G. Biroli, "Jamming: A New Kind of Phase Transition," Nature Physics 3, 222 - 223 (2007) [11]

Selected Presentations:

1. A.S. Keys, C.R. Iacovella, S.C. Glotzer, "Characterizing Structure in Assembled Systems using Shape Matching," FOMMS, Blaine WA (2009) poster
2. A.S. Keys, P. Varilly, S.C. Glotzer and D. Chandler, "LibTPS: A Transition Path Sampling Library," Molecular Kinetics 2009, Berlin Germany (2009) poster
3. S.C. Glotzer, A.S. Keys, C.R. Iacovella, "Molecular Simulation Modules In Undergraduate And Graduate Education: Examples From Molecular Engineering," TMS Annual Meeting, San Francisco CA, (2009)
4. A.S. Keys and S.C. Glotzer, "How Do Quasicrystals Grow?" TMS Annual Meeting, San Francisco CA, (2009)
5. A.S. Keys, S.C. Glotzer, “Mechanism of quasicrystal nucleation and growth,” American Physical Society, March Meeting, Denver CO, (2007) [12].
6. A.S. Keys and S.C. Glotzer, and D.J. Durian, “Growing length scale for dynamical heterogeneity in an air-driven granular system near jamming,” American Physical Society, March Meeting, Denver CO, (2007) [13] .
7. A.S. Keys and S.C. Glotzer, and D.J. Durian, “Spatially Heterogeneous Dynamics and String-like Motion in Granular Matter and Comparison with Glass-Forming Liquids,” American Institute of Chemical Engineers Annual Meeting, San Francisco, CA (2007) [14].
8. A.S. Keys and S.C. Glotzer, “Nucleation and Growth of Quasicrystals,” American Institute of Chemical Engineers Annual Meeting, Cincinnati OH, (2006) [15] .
9. A.S. Keys and S.C. Glotzer “Effect of Local Icosahedral Ordering on Supercooled Liquid Stability Against Nucleation,” American Institute of Chemical Engineers Annual Meeting, Austin TX, (2005) [16].

Projects:

Nucleation and Growth in Supercooled Liquids

Research Area: Condensed Matter Physics; Tools used: C/C++, Matlab. Details: The goal of this project is to explore nucleation and growth in various model liquids using Monte-Carlo simulations. The project involves creating new Monte-Carlo algorithms to enhance statistical sampling of nucleation, which is a rare, activated event. As a result of this project, we have gained fundamental insight into the effect of local icosahedral ordering on nucleation and growth, including the growth of rare quasicrystalline phases.

A quasicrystal nucleus (yellow atoms) grows from a bulk liquid (blue) by assimilating icosahedral clusters (red) whose formation is favoured in a supercooled liquid. (Atoms are shown at 60% of their actual size relative to the space they occupy.) Image by A.S. Keys and C.R. Iacovella.

Glass Transition in Supercooled Liquids and Related Materials

Research Area: Condensed Matter Physics, Fluid dynamics; Tools used: C/C++, Details: This project focuses on understanding the anomalous dynamical behavior exhibited by supercooled liquids and related materials near the glass transition. The project involves determining new algorithms for characterizing liquid dynamics in diverse systems. As a result of this project, we have demonstrated that liquid dynamics can be accurately modeled by hard-sphere granular systems.

An instantaneous bead configuration where the colour of the beads indicates the relative mobility on a timescale over which the mobile cluster size and string length are at a maximum. The 10% most mobile beads are red; note that they form clusters. Beads moving in strings have vectors superimposed to indicate their directional motion. Note that the dynamics are spatially heterogeneous. Image by A.S. Keys.

Shape Matching Applied to Particle Systems

In many computer science applications, a technique known as "shape matching" is used to identify unknown structures. Common applications include retrieving fingerprints from a criminal database or verifying signatures electronically. In the context of particle systems, we can use shape matching methods to create highly-specific ad hoc order parameters. Our scheme involves associating "shape descriptors" with structural patterns of interest and obtaining order parameters by matching with known reference structures. We show that shape matching techniques can be applied to a variety of structural characterization problems such as local and global identification and classification, automated phase diagram mapping, and constructing spatial and temporal structure correlation functions. Our techniques are applicable over a wide range of systems, both simulated and experimental, provided particle positions are known or can be detected with high accuracy. To aid in the development and dissemination of these techniques, we provide a C++/python open-source library to perform shape matching analysis.

Teaching

• GSI experience
  • Eng 101: Introduction to Computers and Programming (Section 109, Atkins) -- GSI
  • Eng 101: Introduction to Computers and Programming (Section 112, Atkins) -- GSI
  • Eng 101: Introduction to Computers and Programming (Section 114, Atkins) -- GSI

• Involvement in other courses:
  • ChE 230: Introduction to Thermodynamics (Solomon / Linderman) -- Coordinated virtual labs
  • ChE 496: Molecular Engineering (Solomon / Burns) -- Coordinated virtual labs
  • MSE 557 / ChE 557: Computational Nanoscience of Soft Matter (Glotzer) -- Unofficial TA / Coordinated virtual labs

Software

• My Projects: LibTPS -- Transition path sampling library, Glotzilla++ -- Glotzilla simulation library (defunct), LibSMGZ -- Glotzilla shape matching library, LibSHD -- Dynamical Analysis, vmdstream -- Communicate with VMD from C++ using a TCP connection
• Other Projects: HOOMD-Blue -- Molecular simulations on the GPU (contributer), Molecular Simulation API -- API to encompass all molecular simulations (contributer)

Personal Interests:

Ice-hockey, classical music