EPSRC PhD in Physics and Astronomy: Quantum optics of giant rydberg excitons in cuprous oxide
has a slightly larger band gap than silicon, which means that the
single crystal form of the material is slightly transparent in the
visible part of the spectrum. Cuprous oxide exists in nature and
beautiful deep-red gemstones have been cut and polished from natural
single crystal material. There has been renewed recent interest in
cuprous oxide as a technological material because of potential
applications in photocatalysis and solar energy harvesting.
oxide has an additional extraordinary optoelectronic property. In most
semiconductors, photons with energy just larger than the band gap can
produce bound electron-hole states known has excitons.
excitons are not unlike hydrogen atoms trapped in the solid-state: they
consist of an electron orbiting a positive core (hole).
hydrogen, the excitons also have excited states, which typically take
the form of Rydberg series, and at cryogenic temperatures it is usually
possible to observe a small number (three or four) excited states. Due
to the unusual nature of the Fermi surface in cuprous oxide, however,
very high principal quantum number excitons states can exist.
recent Nature paper reported Rydberg series extending up to n = 25. This
means that the exciton in cuprous oxide is an extraordinarily stable
quantum object, and one that can be readily manipulated with light.
student will be trained in the use of a range of advanced spectroscopic
characterisation tools, including ultrafast lasers, time-resolved
transient FT-IR, and the latest cryogenic techniques.
This job comes from a partnership with Science Magazine and