Yuejian Wang, from the Department of Physics, Oakland University, presents: The application of high-pressure technique in condensed matter physics.
Pressure along with temperature and chemical composition defines the state of matter. High pressure could decrease the distance among atoms, shorten the chemical bonds, and distort the electron orbitals. Beyond a certain pressure point, materials may reach a new state of equilibrium and transit into a phase with distinctive atomic arrangement and crystal structure exhibiting properties quite different from that stable phase at ambient conditions. For example, under high pressure soft and black graphite transforms into a superhard and light-transparent diamond. With the rapid development of technology (high pressure generation apparatus, synchrotron X-ray, Raman), high-pressure technique has become a prevalent and important tool for exploring the unique nature of matter in solid, liquid, or gaseous state under extreme conditions. In the talk, I will briefly go over the basicsof the high-pressure technology, its advantages, and its application in condensed matter physics as well as the new progressin the study of graphite under high pressure.