Single‐electron control in solid state devices
Janine Splettstoesser, R. J. Haug
This special issue of physica status solidi (b) on single electron control contains a series of articles dealing with the manipulation and detection of single electrons. Based on the tremendous experimental and theoretical progress achieved within this field during the last years, the generation of single electrons on demand in coherent conductors and the full control over the quantum states of single electrons is now within reach. The knowledge of such techniques is an absolute prerequisite for the implementation of schemes for the controlled transfer of quantum information in electronic setups. The transfer of quantum information was up to now mostly applied in quantum-optical setups. Such quantum technologies are expected to open up a whole new field for basic science but also for future applications in quantum communication and quantum sensing. The idea to put in place this special issue arose during a focus session on “single-particle sources for electronic devices”, which we organized at the DPG spring meeting of the condensed matter section in Regensburg on March 7, 2016. During the focus session, it became evident that the advancement of this research field had been quite dramatic during the last years and that it would be helpful for the scientific community to document this progress in a special issue. The focus session in Regensburg included 6 invited and 8 contributed talks. Most of the research groups, which were active in that focus session at the DPG spring meeting, and several other groups have now contributed with manuscripts to this special issue. The leading role of European groups in the field of single-electron control is evident from the fact that most of the contributions are of European origin. Within Europe, in these days, a number of different activities are started to advance quantum technologies, to mention only as a prominent example, the announcement and planning of the 3rd EU Flagship Program on Quantum Technologies. The purpose of this issue is, among others, to bring the field of single-electron control to the attention of the scientific community interested in quantum technologies. This issue includes 10 feature articles, allowing the readers to get a broad overview, but also 11 original research papers, thereby presenting the most recent advancements of the field. The subjects that are covered range from the physics of single-electron wave packets, thermodynamics with single electrons, studies of entanglement and electron quantum optics, up to the realization of feedback control and investigations of single-electron charge transfer. Contributions from experimental groups and from theory groups are almost balanced, representing a complete picture of the field. We hope that all readers will find this issue interesting and stimulating. We dedicate this special issue to Prof. Dr. Tobias Brandes, who unexpectedly passed away on 2 February 2017 at the age of 50. With him we lost an excellent scientist with great international recognition who impressed by his extraordinary kindness and his modest, open and friendly way in meeting people. Throughout his whole scientific carreer, Tobias has worked to bridge the gap between coherent solid-state devices, as e.g. in the quantum Hall effect or in quantum dots, and quantum optics. A focus of his research were quantum mechanical aspects of dynamical effects in solid-state devices. After having studied physics at the University of GÖttingen, Tobias worked at a number of different places, in Germany, Japan and the UK, before he moved to the Technical University of Berlin as a full professor in 2016. Within this special issue one of his last manuscripts is published which deals with feedback control applied to single-electron devices. Feedback control, as he had in mind in some of his recent publications, is therefore also visualized in the picture of the title page of this issue. With the sudden death of Tobias, the whole scientific community lost a great scientist and we all lost a good friend. Janine Splettstoesser Rolf J. Haug Guest Editors
physica status solidi (b)•Mar 1, 2017•23 citations