Theory of Complex Quantum Systems

Rudolf Mößbauer Tenure Track Professor Prof. Robert König has founded the Focus Group Theory of Complex Quantum Systems.

Quantum technologies can provide new information-processing primitives beyond those realizable based on classical physics only. As our ability to create, manipulate and measure quantum systems improves with increasing experimental sophistication, advancing our theoretical understanding of the potential of quantum information processing becomes highly relevant.

This Focus Group studies mathematical questions arising from operational considerations related to quantum systems. This includes fundamental primitives such as communication, cryptography and computation. Areas of emphasis are the design and assessment of suitable mechanisms for the fault-tolerant preparation, processing and readout of quantum information in many-body systems, as well as the estimation of capacities of quantum channels. New insights into the entanglement structure of systems with many degrees of freedom can in turn be applied to variational quantum physics and the development of simulation methods.

TUM-IAS funded postdoctoral researcher:
Dr. Milan Mosonyi (2015-2016)

TUM-IAS funded doctoral candidates:
Stefan Huber (PhD in 2019), Theory of Complex Quantum Systems

Publications by the Focus Group

2020

  • Kliesch, Alexander; König, Robert: Continuum Limits of Homogeneous Binary Trees and the Thompson Group. Physical Review Letters 124 (1), 2020 more…

2019

  • Bluhm, Andreas; Stilck França, Daniel: Dimensionality reduction of SDPs through sketching. Linear Algebra and its Applications 563, 2019, 461-475 more…
  • Bravyi, Sergey; Gosset, David; König, Robert; Tomamichel, Marco: Quantum advantage with noisy shallow circuits in 3D. 2019 more…
  • Bravyi, Sergey; Kliesch, Alexander; König, Robert; Tang, Eugene: Obstacles to State Preparation and Variational Optimization from Symmetry Protection. 2019 more…
  • Bravyi, Sergey; Gosset, David; König, Robert; Temme, Kristan: Approximation algorithms for quantum many-body problems. Journal of Mathematical Physics 60 (3), 2019, 032203 more…
  • Fukuda, Motohisa; König, Robert: Typical entanglement for Gaussian states. Journal of Mathematical Physics 60 (11), 2019, 112203 more…
  • Fukuda, Motohisa; König, Robert; Nechita, Ion: RTNI—A symbolic integrator for Haar-random tensor networks. Journal of Physics A: Mathematical and Theoretical 52 (42), 2019, 425303 more…
  • Gschwendtner, Martina; König, Robert; Şahinoğlu, Burak; Tang, Eugene: Quantum error-detection at low energies. Journal of High Energy Physics 2019 (9), 2019 more…
  • Heinze, Margret; König, Robert: Universal Uhrig Dynamical Decoupling for Bosonic Systems. Physical Review Letters 123 (1), 2019 more…
  • Huber, Stefan; König, Robert; Tomamichel, Marco: Jointly constrained semidefinite bilinear programming with an application to Dobrushin curves. IEEE Transactions on Information Theory, 2019, 1-1 more…

2018

  • Bravyi, Sergey; Englbrecht, Matthias; König, Robert; Peard, Nolan: Correcting coherent errors with surface codes. npj Quantum Information 4 (1), 2018 more…
  • Bravyi, Sergey; Gosset, David; König, Robert: Quantum advantage with shallow circuits. Science 362 (6412), 2018, 308-311 more…
  • De Palma, Giacomo; Huber, Stefan: The conditional entropy power inequality for quantum additive noise channels. Journal of Mathematical Physics 59 (12), 2018, 122201 more…
  • França, D S; Hashagen, A K: Approximate randomized benchmarking for finite groups. Journal of Physics A: Mathematical and Theoretical 51 (39), 2018, 395302 more…
  • Huber, Stefan; König, Robert: Coherent state coding approaches the capacity of non-Gaussian bosonic channels. Journal of Physics A: Mathematical and Theoretical 51 (18), 2018, 184001 more…
  • Müller-Hermes, Alexander; Franca, Daniel Stilck: Sandwiched Rényi Convergence for Quantum Evolutions. Quantum 2, 2018, 55 more…
  • Stilck Franca, Daniel: Perfect sampling for quantum Gibbs states. Quantum Information and Computation 18 (5&6), 2018, 361-388 more…

2017

  • Hiai, Fumio; König, Robert; Tomamichel, Marco: Generalized Log-Majorization and Multivariate Trace Inequalities. Annales Henri Poincaré 18 (7), 2017, 2499-2521 more…
  • Hiai, Fumio; Mosonyi, Milán: Different quantum f-divergences and the reversibility of quantum operations. Reviews in Mathematical Physics 29 (07), 2017, 1750023 more…
  • Huber, Stefan; König, Robert; Vershynina, Anna: Geometric inequalities from phase space translations. Journal of Mathematical Physics 58 (1), 2017, 012206 more…
  • Idel, Martin; König, Robert: On quantum additive Gaussian noise channels. 2017 more…
  • König, Robert; Scholz, Volkher B.: Matrix product approximations to conformal field theories. Nuclear Physics B 920, 2017, 32-121 more…
  • Mosonyi, Milán; Ogawa, Tomohiro: Strong Converse Exponent for Classical-Quantum Channel Coding. Communications in Mathematical Physics 355 (1), 2017, 373-426 more…

2016

  • Beverland, Michael E.; Buerschaper, Oliver; Koenig, Robert; Pastawski, Fernando; Preskill, John; Sijher, Sumit: Protected gates for topological quantum field theories. Journal of Mathematical Physics 57 (2), 2016, 022201 more…
  • Beverland, Michael E.; Buerschaper, Oliver; König, Robert; Pastawski, Fernando; Preskill, John; Sijher, Sumit: Protected gates for topological quantum field theories. Journal of Mathematical Physics 57 (2), 2016, 022201 more…
  • Cooney, Tom; Mosonyi, Milán; Wilde, Mark M.: Strong Converse Exponents for a Quantum Channel Discrimination Problem and Quantum-Feedback-Assisted Communication. Communications in Mathematical Physics 344 (3), 2016, 797-829 more…
  • König, Robert; Scholz, Volkher B.: Matrix Product Approximations to Multipoint Functions in Two-Dimensional Conformal Field Theory. Physical Review Letters 117 (12), 2016 more…
  • Ni, Xiaotong; Pastawski, Fernando; Yoshida, Beni; König, Robert: Preparing topologically ordered states by Hamiltonian interpolation. New Journal of Physics 18 (9), 2016, 093027 more…

2015

  • König, Robert: The conditional entropy power inequality for Gaussian quantum states. Journal of Mathematical Physics 56 (2), 2015, 022201 more…
  • Mosonyi, Milan; Ogawa, Tomohiro: Two Approaches to Obtain the Strong Converse Exponent of Quantum Hypothesis Testing for General Sequences of Quantum States. IEEE Transactions on Information Theory 61 (12), 2015, 6975-6994 more…