Computational Materials Science Seminars
- “Tokyo University developed a technique to accurately calculate metal, a semiconductor and an insulator.,
- “Fujitsu Laboratories Ltd. has successfully simulated the electrical properties of a 3,000-atom nano device”,
- “JAIST succeeded in Experimental Evidence for Epitaxial Silicene on Diboride Thin Films -”，
日刊工業新聞, 共同通信, 京都新聞, 四国新聞社, 大分合同新聞社2012/5/30
- “Fujitsu Succeeds at Large-Scale Calculations Enabling the Computational Design of Novel Nanodevices”,
Past News (Until May 2014 at JAIST)
The study entitled "Systematic study of electronic and magnetic properties for
Cu12-xTMxSb4S13 (TM=Mn, Fe, Co, Ni, and Zn) tetrahedrite"
was published in J. Appl. Phys. (Published online April 9). The research was conducted in collaboration with
Dr. Suekuni of Hiroshima University and Prof. Koyano's group of JAIST.
J. Appl. Phys. 115, 143702 (5 pages) (2014)
- The study entitled "Microscopic origin of the π states in epitaxial silicene" from collaborative work of Takamura-Yamada group (School of Materials Science, JAIST), Hasegawa group (ISSP, Univ. Tokyo), and Ozaki group was published in Appl. Phys. Lett. (Published online January 16). Appl. Phys. Lett. 104, 021605 (4 pages) (2014)
Past Seminars (Until May 2014 at JAIST)
"Simulation Science" Seminars hosted by RCSS, JAIST
- 8th Simulation Science Seminar
- TITLE: Understanding the STM and AFM contrast in graphene, reducible oxides and biomolecules
- SPEAKER: Ruben Perez (Professor, Theory of Condensed Matter Department, Universidad Autonoma de Madrid, http://www.uam.es/spmth/)
- DATE/TIME: 2013 Nov. 18, 15:00-16:30
- SUMMARY: We’ll review the computational tools and protocols developed in our group in order to study the mechanical
and transport properties of materials, and its application to the understanding of
the atomic-resolution images obtained with the scanning tunneling (STM)
and the force microscope (AFM) by different experimental groups on technologically relevant materials.
Firstly, we’ll focus on tuning of the electronic properties of graphene through the creation of defect
and edge states, looking, in particular, to the connection of graphene with metal surfaces.
Combining high resolution STM experiments and DFT calculations,
we have unambiguously unveiled the atomic structure of the boundary between a graphene zigzag edge
and a Pt(111) step. The graphene edges minimize their strain by inducing a 3-fold edge-reconstruction
on the metal side. We have shown the existence of an unoccupied electronic state
exclusively localized in the C-edge atoms of a particular graphene sublattice,
which could be used to develop new dual-channel devices.
Metal oxides play a key role in a wide range of technological applications.
While in many cases the same FM-AFM image can be explained by different models,
and even different underlying tip-sample interactions, we show here that the combination
of force spectroscopy (FS) measurements and first-principles simulations
can provide an unambiguous identification of the tip structure and the image contrast mechanism
in rutile TiO2 (110) and anatase TiO2 (101) surfaces. In the case of STM,
we have made a comprehensive study of the (2√2x√2)R45゜ missing row reconstruction
of the Cu(100) surface, using different tips and systematically varying bias voltage
and tip sample distance, to explore the rich variety of image contrasts observed in the experiments.
Our results achieve a conclusive understanding of fundamental STM imaging mechanisms
and provide guidelines for experimentalists to achieve chemically selective imaging
by selecting imaging parameters.
Finally, we’ll present our recent work on the structure and functionality of biological systems
in their native liquid environment. We’ll discuss the application of large-scale steered
Molecular Dynamics simulations, based on classical potentials developed by the molecular biology community
and the use of GPUs as processing units, provide insight into the protein-graphene biocompatibility,
the flexibility map of human antibodies, and the hydration properties of self-assembled monolayers
of single-stranded DNA and its possible use as a label-free DNA sensor.