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Cuprous oxide has been widely recognized as a possible host material for an excitonic condensation owing to its favorable band structures. However, the difficulty in reaching the condensed state lies in a strong two-body process at high densities. This work is an experimental and theoretical study of excitonic lifetimes due to various relaxation processes. A generalized exciton/acoustic-phonon interaction is classified in order to explain 1) thermalization (scalar field scattering), 2) ortho-para down-conversion (axial vector field scattering), and 3) singlet-doublet interconversion (off-diagonal tensor field scattering) under external stress. A density-dependent exciton recombination process is carefully investigated in terms of 1) mutual spin-flip scattering, 2) excitonic Auger recombination, and 3) exciton-exciton capture to form an optically inactive biexciton. A theoretical modeling of the exciton kinetics is proposed to explain experimental observations and possibilities of Bose-Einstein condensation of excitonic matter in this unique semiconductor.

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Joon Jang specializes in the area of condensed matter physics and nonlinear optics. He received Ph.D. in physics from UIUC in 2005. Dr. Jang joined the Physics Department at Binghamton University in 2010 after his postdoctoral work at Northwestern University. He edited New Developments in Photon and Materials Research , NOVA Scientific Publishers.

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