Quantum memories are a basic building block of quantum networks, where they serve to synchronise information. Memories are also a crucial component of the quantum repeaters that will allow long distance quantum communication. For these applications, memories must have high data storage densities, but these have proven hard to achieve.

Low concentration rare earth materials have emerged as a leading quantum memory platform, and have shown long storage times, high efficiencies, and the potential for large bandwidths. Achieving high data storage densities, however, will require higher ion densities than are currently used. I will explain how high data storage densities might be reached by making memories using fully concentrated rare earth crystals.

With higher ion densities, the interactions between rare earth ions become increasingly important and are likely to place ultimate limits on the storage density. I will describe how these interactions can be characterised and how their effects might be mitigated.

Dr Rose Ahlefeldt received her PhD from ANU in 2013. She worked as a post-doc at Laboratoire Aimé Cotton in Orsay, France, for one year before winning a Fulbright Postdoctoral Scholarship to travel to the US. For her Fulbright project she spent a year working at Montana State University in Bozeman. In 2016, she returned to Australia and was awarded a DECRA fellowship.  Rose’s research focuses on  two main areas: the development of materials for quantum information applications, particularly quantum memories and quantum computers, and the study of ion-ion interactions in rare earth crystals using high-precision spectroscopy techniques

Refreshments will be held in the Tea Room after the Seminar (around 4pm)

All welcome