Engineered Quantum States

Project 2:

Quantum states with ‘exotic’ non-local properties might lead to novel approaches to processing and storing information. We explore various routes to creating, studying and eventually exploiting such states.

Project leaders: Ataç Imamoglu, Klaus Ensslin, Werner Wegscheider

Members: Klaus Ensslin, Jérôme Faist, Anna Fontcuberta i Morral, Andreas Fuhrer, Thomas Ihn, Ataç Imamoglu, Tobias J. Kippenberg, Jelena Klinovaja, Daniel Loss, Frédéric Merkt, Alberto Morpurgo, Gian Salis, Matthias Troyer, Andreas Wallraff, Werner Wegscheider, Dominik Zumbühl

Many-body systems exhibit phases that cannot be described by local properties alone. An important recent example is that of topological insulators, which have the counterintuitive property that they are electrical insulators in the inside but conduct electricity on the surface. Topological order can also be used to represent quantum information non-locally. The system then becomes insensitive to local fluctuation, making it in turn more robust against external disturbances and therefore particularly suitable for applications.

The goal of this project is to develop basic concepts based on topological protection for quantum information processing and to engineer and study complex solid-state systems that can be prepared in topological quantum phases. These systems hold the promise to provide novel approaches to quantum computation and fault-tolerant quantum memory. The exploratory research on exotic or hybrid quantum systems performed in this project is complementary to that on well-studied qubits for basic quantum information processing.

Towards these goals, we pursue a broad variety of topics, involving different material systems, several experimental techniques and accompanying theoretical work. In connection with experimental activities we also fabricate new materials that host, for example, fractional quantum Hall states and helical spin states, and we develop novel hybrid architectures to couple electronic systems to cavities in the optical, terahertz or microwave range.