ICAMS / Interdisciplinary Centre for Advanced Materials Simulation


Quantum‐mechanical combinatorial design of solids with target properties

Date: 23.11.2010
Time: 13:00
Place: Materials Discovery by Scale‐Bridging High‐Throughput Experimentation and Modelling Workshop, Ruhr-Universität Bochum, Bochum, Germany

Alex Zunger, Department of Solid State Theory, National Renewable Energy Laboratory (NREL), Golden, USA

This talk will focus on the way atomistic electronic structure calculations are combined with evolutionary algorithms to scan a truly astronomic number of atomic configurations in search of the one(s) that have desired ,target electronic properties. Thus, instead of using atomic structure ( configuration) as input and electronic properties as output ,we will do the reverse: use electronic properties as input and obtain configuration as output. The rational for trying such an inverse approach is as follows:

(1) One of the most striking aspects of solid state physics is the diversity of structural forms in which crystals appear in Nature. The already rich repertoire of such (equilibrium) forms has recently been significantly enriched by the advent of artificial growth techniques (MBE, STM‐atom positioning ,etc.) that can create desired structural forms, such as superlattices and geometric atomic clusters even in defiance of the rules of equilibrium thermodynamics.

(2) As is well known, different atomic configurations generally lead to different physical properties even at fixed chemical composition. While the most widely‐known illustration of such “form controls function” rule is the dramatically different color, conductivity and hardness of the allotropical forms of pure carbon, the physics of semiconductor superstructures and nanostructures is full of striking examples of how optical, magnetic, and transport properties depend sensitively on atomic configuration (e.g., compare the properties of random to ordered alloys).

(3) Yet, the history of material research generally proceeded via accidental discoveries of materials configuration with interesting physical property (semiconductivity, ferromagnetism; superconductivity, etc.).

(4) Given the ability of growing many different atomic configurations, and given the often sensitive dependence of physical properties on atomic configuration, makes one wonder: can one first articulate the desired target physical property, then search (within a class) for the configuration that has this property?

Supporting information:

Materials Day_Zunger.pdf
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