Frontier Research Institute for Interdisciplinary Sciences
Tohoku University

Electron possesses "spin", a magnetic degree of freedom, as well as electric charge. They can be coupled together by "spin-orbit coupling" to show various phenomena, which have recently been applied to development of new electronic devices, such as high-efficiency memories and transistors. It is strongly required to propose such novel phenomena from the theoretical side.

There is a special class of matter called "Dirac semimetal", which is suggested as a candidate for showing such nontrivial electronic properties. Dynamics of electrons in Dirac semimetals is quite different from that in normal metals and semiconductors, which obeys the same rules as for elementary particles in early universe and accelerators, called “Dirac equation”. Thus one can expect that Dirac semimetals can show any nontrivial physics ruling early universe, which may be used for further applications.

My research aims to propose unknown electronic properties in Dirac semimetals, making use of such an analogy between the theory of Dirac electrons and that of elementary particles in early universe. In particular, I am focusing on the "correlation" of electrons -- how the electric and magnetic interaction between electrons can change the collective properties of electrons. Based on the analogy to early universe, I am trying to apply some well-established techniques in that field to my analysis, such as "quantum field theory" and "lattice gauge theory". New behavior of electrons obtained in this analysis may modify charge and spin transport properties, which can be applied for further development of electronic devices.