TRR 183:  Entangled States of Matter

• Subject Area: Physics
• Term: since 2016
• Website: Homepage
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 277101999

The mission of our collaborative research center (CRC) is to exploit the fundamental laws of quantum mechanics to materialize many-body entanglement in condensed matter systems and to devise and implement protocols to manipulate its dynamics. A salient feature of entangled states of matter is that the large number of atomistic constituents in a solid may mutually protect each other against the detrimental effects of decoherence. The emergence and manipulation of entanglement on such macroscopic scales hinges on the interplay of three concepts, which also define the research areas of our CRC: (i) Topological quantum matter. Entangled states of large quantum systems owe their existence to protection mechanisms of topological origin. A quantum wave function characterized by a non-trivial topological index – a ‘knotted’ wave function, so to speak – shows a high degree of robustness against detrimental mechanisms of decoherence. The ensuing stable topological excitations are microscopic building blocks central to the construction of entangled states of matter. (ii) Quantum information. The advent of entangled quantum matter in solid-state realizations has given rise to a ‘hands-on’ approach in quantum information theory. Concepts of quantum information are harnessed in practical settings, such as the implementation of quantum circuits to dynamically create and manipulate entanglement structures on noisy intermediate scale quantum platforms. Conversely, the experimental reality of noise-related sources of decoherence is addressed by exploring how disorder effects themselves can be used to stabilize quantum information. (iii) Quantum Devices. The interplay of the physical ramifications of entanglement and quantum information protocols to actively steer entangled states, leads to proposals of novel condensed matter device architectures. Closely intertwined theoretical and experimental research on such quantum devices addresses the physics of fractionalized excitations, and specifically their realization in correlated materials, or in micron sized mesoscopic systems comprising semiconducting, metallic and superconducting hybrid elements. These systems serve as platforms for the design of practical quantum computing architectures.

• DFG Programme: CRC/Transregios
• International Connection: Denmark, Israel

Current projects

• A01 - Topology and dynamics (Project Heads Berg, Erez ;  Brouwer, Piet W. ;  Rosch, Achim )
• A02 - Gapless topological phases (Project Heads Beidenkopf, Haim ;  Breitkreiz, Maxim ;  Brouwer, Piet W. ;  Diehl, Sebastian ;  Egger, Reinhold ;  Reuther, Johannes ;  Yan, Binghai )
• A03 - Entanglement and Disorder (Project Heads Alldridge, Alexander ;  Altland, Alexander ;  Brouwer, Piet W. ;  Eisert, Jens ;  Zirnbauer, Martin R. )
• A04 - Theory of fractionalized topological phases of matter (Project Heads Berg, Erez ;  Hermanns, Maria ;  Mross, David ;  Oreg, Yuval ;  Reuther, Johannes ;  Rizzi, Matteo ;  Ronen, Yuval ;  Stern, Adiel ;  Trebst, Simon )
• B01 - Entanglement (Project Heads Buchhold, Ph.D., Michael ;  Eisert, Jens ;  Gross, Ph.D., David ;  Kastoryano, Michael ;  Rizzi, Matteo ;  Trebst, Simon ;  Turkeshi, Ph.D., Xhek )
• B02 - Measurement and control of open quantum matter (Project Heads Diehl, Sebastian ;  Egger, Reinhold ;  Eisert, Jens ;  Gefen, Yuval ;  Kastoryano, Michael ;  Koch, Christiane ;  Pappalardi, Ph.D., Silvia ;  Rudner, Mark )
• B04 - Synthetic and holographic quantum matter (Project Heads Altland, Alexander ;  Bagrets, Dmitry ;  Callebaut, Nele ;  Egger, Reinhold ;  Eisert, Jens ;  Gefen, Yuval ;  Oreg, Yuval )
• C01 - Measurement and manipulation of entanglement (Project Heads Diehl, Sebastian ;  Egger, Reinhold ;  Flensberg, Karsten ;  Gefen, Yuval ;  Marcus, Charles M. )
• C02 - Engineering topological states of matter (Project Heads Berg, Erez ;  Ilani, Shahal ;  von Oppen, Felix ;  Oreg, Yuval )
• C03 - Hybrid topological platforms (Project Heads Franke, Katharina ;  Michaeli, Karen ;  von Oppen, Felix ;  Stern, Adiel ;  Vaitiekenas, Saulius )
• C05 - Transmon and superconducting qubits (Project Heads Altland, Alexander ;  Flensberg, Karsten ;  Koch, Christiane ;  Metelmann, Anja ;  Trebst, Simon )
• Z - Administration (Project Heads Altland, Alexander ;  Trebst, Simon )

Completed projects

• B01 - Quantum error correction and new phases of matter (Project Head Kastoryano, Michael )

• Applicant Institution: Universität zu Köln
• Co-Applicant Institution: Freie Universität Berlin; Weizmann Institute of Science
• Participating University: Heinrich-Heine-Universität Düsseldorf; Københavns Universitet
• Participating Institution: Forschungszentrum Jülich
• Spokespersons: Professor Dr. Alexander Altland, until 3/2018; Professor Dr. Simon Trebst, since 4/2018