SFB 631:  Solid State Based Quantum Information Processing: Physical Concepts and Materials Aspects

• Subject Area: Physics
• Term: from 2003 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5485864

In the Collaborative Research Centre research groups from the Bavarian Academy of Sciences, the Technical University of Munich, the Ludwig-Maximilians-University Munich, the Max-Planck-Institute for Quantum Optics, as well as the University of Regensburg and the University of Augsburg are collaborating within 15 projects. In addition to 30 senior scientists, more than 30 PhD and diploma students as well as a large number of guests are involved in the research activities.
The research activities are directed towards the interdisciplinary research field of Solid State Based Quantum Information Processing which is involving ideas and concepts from information theory, physics, mathematics and materials science. This research initiative is aimed at the basic understanding of the fascinating physics as well as the materials and technological aspects of solid state based quantum information processing. The key questions to be attacked are:
-- How can we realise solid state based quantum bits with sufficiently large quantum coherence?
-- How can we control, manipulate, couple and effectively read out these phase coherent quantum states?
-- How can we scale individual solid state based quantum bits to more complex systems?
-- Which concepts can we employ to reduce decoherence effects?
-- Which degrees of freedom in solid state systems are most suitable for the implementation of solid state based quantum bits?
-- How can we solve the materials issues and technological problems showing up in the realisation of solid state based quantum bits?
-- How can we establish an interface between solid state based quantum bits and quantum communication systems?
To answer these questions research activities in the fields of quantum information theory, experimental and theoretical solid state physics, quantum optics, materials science and nanotechnology are coordinated. The long-term goal of the coordinated research is to develop a deep understanding of physical concepts of solid state based quantum information processing and to establish the materials and technology basis for a successful implementation of solid state based quantum bits. In this way the vision of realising useful quantum information systems including quantum computing and quantum communication can be approached.

• DFG Programme: Collaborative Research Centres
• International Connection: Austria, United Kingdom

Completed projects

• A01 - Electrostatically Defined Quantum Dots as Qubits (Project Heads Kotthaus, Jörg Peter ;  Ludwig, Stefan )
• A02 - Theory of Superconducting Qubits (Project Heads von Delft, Jan ;  Marquardt, Florian Kai ;  Siewert, Jens )
• A03 - Superconducting Quantum Circuits as Basic Elements for Quantum Information Processing (Project Heads Gross, Rudolf ;  Hübl, Hans ;  Marx, Achim )
• A05 - Control of Decoherence in Solid State Based Quantum Information Systems (Project Head Hänggi, Peter )
• A06 - Theory of Many-particle Entanglement and its Application in Solid-State Systems (Project Heads Cirac, Juan Ignacio ;  Giedke, Géza ;  Siewert, Jens )
• A07 - Circuit modeling of interaction between electromagnetic fields and superconducting flux qubits (Project Heads Csaba, György ;  Lugli, Paolo )
• A08 - Cavity Quantum Electrodynamics with Superconducting Devices (Project Heads Gross, Rudolf ;  Marx, Achim )
• A09 - Optimal Control Methods and Applications in Solid-State Systems (Project Head Glaser, Steffen )
• A10 - Theory of Superconducting Qubits (Project Head Grifoni, Milena )
• A11 - Cavity QED with Carbon Nanotube Quantum Dots using Superconducting Resonators: Charge and Spin Qubits (Project Heads Hüttel, Andreas Klaus ;  Strunk, Christoph )
• A12 - Quantum Correlations in Cavity-Waveguide Networks (Project Head Hartmann, Michael J. )
• B01 - Spin-dependent Spectroscopy of Electronic States in Individual and Coupled Quantum Dots (Project Heads Abstreiter, Gerhard ;  Koblmüller, Gregor )
• B02 - Optical Manipulation of Two-Level Solid State Quantum Systems (Project Heads Holleitner, Alexander Walter ;  Weinfurter, Harald )
• B03 - Integrated on-chip Single Photon Quantum Optics (Project Heads Amann, Markus-Christian ;  Finley, Jonathan J. ;  Kaniber, Michael )
• B04 - Einzelatome als Modelle für quantenpunktbasierte Quanteninformationssysteme (Project Heads Kuhn, Axel ;  Rempe, Gerhard )
• B05 - Ultrafast Electro-optical Control of Spins in Few Quantum Dot Nanostructures (Project Heads Finley, Jonathan J. ;  Holleitner, Alexander Walter ;  Krenner, Hubert Johannes )
• B06 - Quantum Memory and Quantum Simulations with Ultracold Gases (Project Heads Dürr, Stephan ;  Rempe, Gerhard )
• B07 - Real Time Dynamics of Driven Dissipative Quantum Systems (Project Heads von Delft, Jan ;  Kehrein, Stefan ;  Weichselbaum, Ph.D., Andreas )
• C01 - Theory of Spin-dependent Electronic Structure, Transport Processes and Excitonic Properties in Low-dimensional Semiconductor Structures (Project Heads Scholz, Reinhard ;  Vogl, Peter )
• C02 - Quantenspins mit stark angekopelter Umgebung: Renormierungsmethoden zur Behandlung starker Korrelationen (Project Head von Delft, Jan )
• C03 - Fundamentals of Quantum Logic Gates in Silicon (Project Heads Brandt, Martin S. ;  Hübl, Hans ;  Stutzmann, Martin )
• C04 - Electrostatically Defined Spin Qubits in Si/SiGe: Devices and Materials with Engineered Nuclear Spin Concentration (Project Heads Abstreiter, Gerhard ;  Bougeard, Dominique )
• C05 - Spinabhängiger Transport in nanostrukturierten Festkörpern (Project Heads Gross, Rudolf ;  Marx, Achim ;  Opel, Matthias )
• C06 - Coherent Control of Coupled Spin Systems in Semiconductor Quantum Dots (Project Heads Brandt, Martin S. ;  Finley, Jonathan J. ;  Högele, Alexander ;  Vogl, Peter )
• C07 - Nuclear Spins in Quantum Dots (Project Heads Cirac, Juan Ignacio ;  Giedke, Géza ;  Schliemann, John )
• Z - Central Tasks (Project Head Gross, Rudolf )

• Applicant Institution: Technische Universität München (TUM)
• Participating University: Ludwig-Maximilians-Universität München; Universität Augsburg; Universität Regensburg
• Participating Institution: Bayerische Akademie der Wissenschaften; Max-Planck-Institut für Quantenoptik (MPQ)
• Spokesperson: Professor Dr. Rudolf Gross