4. Quantum information and many-particle systems

(H. Johannesson, V. Shumeiko, G. Ferretti, J. Fuchs, A. Stolin, S. Östlund)

In the last few years there has been a growing interest in quantum many-particle systems from the point of view of quantum information. This interest is driven by the need to go beyond the present understanding of how to operate a few qubits and build scalable and fault-tolerant devices that can be easily controlled and manipulated. New ideas for carrying out quantum information tasks, such as quantum state transfer, has also increased the need to better understand the behavior of many-particle systems. These goals have led to an exchange of ideas between the quantum information and condensed matter communities. As a result, novel approaches inspired by quantum information theory are now actively being pursued for attacking problems in condensed matter physics, an important example being the study of quantum phase transitions in strongly correlated systems. In this project we plan to explore this new arena of research, studying the role of quantum entanglement and non-local correlations in many-particle systems. Specifically, we plan to address the following problems:

* The study of topological ground states in strongly correlated matter, using the tools of conformal field theory to derive their entanglement properties.
* The study of quantum entanglement in nanoscale lattices of spin coupled quantum dots, with focus on competing effects driven by Kondo screening.
* The study of the distribution of entanglement in spiral quantum spin states, controlled by twisted magnetic fields. This project, where we will exploit exact results from the theory of integrable models, will be carried out in collaboration with Yupeng Wang’s group at the Institute of Physics, Beijing.