Physics of Biological Materials and Crystal Growth Laboratory
A Heterogeneous Research Group that unify the research fields of Physics,
Chemistry, and Life Sciences
Our research laboratory is constituted with two research groups of "Physics
of Biological Materials" and Physics of Crystal Growth". These
two research groups are closely related to each other and promoting the
high quality academic education and scientific research projects in order
to explore new frontiers of condensed matter physics. The extreme objective
of our defined terminology " Physics of Biological Materials"
is to explain the biological events (especially photosynthesis in plants,
alga, and bacteria) with the words of the condensed matter physics. Nature
had evolved photosystems in photosynthetic organisms that are gentle to
the environment of the earth and can most effectively utilize the solar
energy after 3.9 billion years of trial and errors. For example, light-harvesting
antenna pigment-protein complexes from purple photosynthetic bacteria have
a beautiful Chrismas-wreath like ring structure with 9-fold symmetry (8-fold
symmetry depending on the species fo bacteria). It is highly required to
clarify the light-harvesting and energy-transferring mechanisms of such
structures in order to open a new door for next generation technology (bio-nanotechnology).
We are mainly focusing our attention to the studies of carotenoid pigments
that are playing essential roles in the primary process of photosynthesis.
X-ray crystal structure analysis has been applied to determine the electron
distribution and molecular structure of the artificial photosynthetic pigment
protein complexes in which the structures of carotenoids are systematically
modified. Simultaaneously the excitation energy transfer mechanisms and
inter-molecular interactions have been determined using various spectroscopic
methods. Through these research works, artificial pigment-protein complexes
that do not exit in nature have been created and the detailed functional
mechanisms are clarified. Our research objective is to interpret the blueprint
of life activity using the words of "condensed matter physics".
Our final goal is to build the new basic ideas that can break through the
old or current ideas in the solar energy conversion processes, to establish
the solid foundation of ultrafast and highly efficient excitation energy-transfer,
and to create completely new condensed matter physics.
In order to gain deeper insight into these fascinating supra-molecular
complex systems, we are also investigating the relationship between molecular
structures and optical responses fo relatively simpler systems (e.g. organic
thin-solid films or bulk crystals). As an example, the generation mechanisms
of terahertz radiation from organic nonlinear crystals are being studied.
Human beings are utilizing light (electromagnetic radiation) with various
frequencies for telecommunication, spectroscopic analyses and medical applications.
However, far-infrared light in the terahertz frequency regime is a light
with unprecedented frequency domain and it is still not put to practical
use because of low efficiency of generation and detection. Exploiting this
frequency regime of light directly connects to create new scinece and technology
as well as the field of condensed matter physics. We are fabricating organic
thin-solid films or bulk crystals in which the structures of the component
molecules are systematically modified based on our unique strategies. The
generation mechanisms of coherent pulsed terahertz radiation from these
organic nonlinear materials have been investigated. We are aiming to create
basic ideas and technologies to generate high power terahertz radiation
using organic optical functioning materials.
Moreover, We are investigating to clarify how various material systems
surrounding us construct the current shapes and why they exist as they
are. When you vaguely look at snowflakes attached to your gloves, probably
you may have experiences to be amazed each one of the snowflakes has their
own beautiful geometrical structures. There are many such kinds of material
systems in our surroundigns. With what kined of mechanisms can nature create
such beautiful structures? We are promoting research projects to ansewer
this question and studying the existence of materials itself. In order
to understand the macrospopic "diversity of the shape" of materials
it is important to hvave the knowledge about the arrangement of atoms or
molecules as well as the elementary process of crystal growth at the surface
of materials. We are making good challenges to quest the mechanisms of
forming the shapes of materials through various kinds of elementary processes
of cyystal growth based on the close inspection in the atomic scale of
the surface structures and the structual phase transition in accordance
with the temperature and pressure changes.
Last update: 9.20. 2013
||Physics of Biological Materials and Crystal Growth Laboratory
Department of Physics, Graduate School of Science
Osaka City University