Invitation to chiral physics

Abstract

Although measurement of the optical activity of solids had been impossible for 170 years since its discovery by Arago (1811), we have developed a method called HAUP (high accuracy universal polarimeter), which enables one to measure simultaneously optical activity, birefringence, and rotation of the indicatrix of any crystals, even those belonging to the monoclinic and triclinic systems. Thus the HAUP has opened a new research field in condensed matter physics. This article reviews our applications of the HAUP method to studies on several unsolved problems in this science. It includes an understanding of the origin of structurally incommensurate phases, a revelation of the twinning mechanism of the ferroelectric domains, the first exploration of optical properties of monoclinic crystals, the determination of correct crystal symmetries of transparent PLZT ceramics, first measurements of anisotropic gyrations of helical polymers, and measurements of reciprocal and non-reciprocal optical activity of high temperature superconductors. It is important to note that these problems could be solved only by making use of the crucial property of optical activity. Summing up the present study, we should like to emphasize the necessity of the new research field, ‘chiral physics’where axial tensors like gyration can play major roles.

Key Words:

• HAUP
• optical activity
• twinning
• incommensurate phase
• superconductivity
• helical polymer