Contact: / Office: MC 1.89 / Tel: +49 (0)234 32-28555

I am a full Professor of Computer Science and head of the Quantum Information group at the Faculty of Computer Science, Ruhr-University Bochum and the CASA Cluster of Excellence.

My research is in quantum information and computation, and their interplay with other branches of computer science, mathematics, and theoretical physics. Motivated by quantum information, I also study problems in optimization, representation theory, and invariant theory through the lens of computation. I am a 2017 Veni laureate and received a 2020 Early Career Award from the Royal Netherlands Academy of Arts and Sciences (KNAW). We are part of the consortium project QuBRA and are also suported by an NWO OC ENW grant.

From 2017 to 2021, I was an Assistant Professor in Mathematics and Theoretical Physics at the University of Amsterdam (KdVI, ITFA, ILLC) and QuSoft. Before that, from 2014 to 2017, I was a Postdoctoral Scholar at Stanford University, hosted by Patrick Hayden. I received my PhD from ETH Zurich in October 2014 and was awarded an ETH Medal.



  • Valerie Bettaque (MSc project)
  • Bjarne Bouwer (MSc project)
  • Harold Nieuwboer (PhD candidate), classical & quantum optimization algorithms
  • Galina Pass (PhD candidate), quantum algorithms
  • Freek Witteveen (PhD candidate), quantum information & field theory
  • Matteo Lostaglio (postdoc)
  • Akshay Ramachandran (postdoc)


  • Jonas Helsen (2019–21, postdoc; now tenure-track researcher at CWI)
  • Ricardo Rivera (2020-21; MSc project; soon PhD student at Slovak Academy of Sciences)
  • Tomas Bosschieter (2021, BSc project on optimal transport and machine learning; now PhD student at Stanford)
  • Friso Lohmann (2021, BSc project on quantum state tomography)
  • Yinan Li (2018-20, postdoc; now designated assistant professor at Nagoya)
  • Marten Folkertsma (2019-20, MSc project on continuous LOCC; now PhD student at CWI)
  • Laurens Ligthard (2019-20, MSc project on quantum entropy; now PhD student at Köln)
  • Maxim van den Berg (2020, BSc project on lossless audio compression)
  • Slawi Dimitrov (2020, BSc project on randomized benchmarking)
  • Emma Loos (2018-19, MSc project on cMERA and holography; now PhD student at WĂŒrzburg)
  • Jeroen Dekker (2018-19, MSc project on holographic tensor networks and smooth entropies)
  • Lars van Geest (2019, BSc project on tensor networks for the Motzkin spin chain)
  • John Paul Marceaux (2019, academic skills project on design theory)
  • Philip Verduyn Lunel (2018-19, MSc project on quantum simulations and many-body localization; now PhD student at CWI)
  • Raja Damanik (2018, MSc project on optimality in stabilizer testing; soon PhD student at Canberra)
  • Casper Guyrik (2018, MSc project on quantum algorithms for factoring and post-quantum RSA, daily supervised by Ronald de Wolf; now PhD student at Leiden)
  • Philip Roeleveld (2018, BSc project on a truncated tensor scaling algorithm)
  • Wouter Borg (2018, BSc project on entanglement in the stabilizer formalism)

Next group meeting: See Slack.

Publications and Preprints

See the arXiv and Google Scholar (and also GitHub).


Fall 2021: Bachelor’s course Introduction to Information Theory [more]

Fall 2021: Master Seminar in Discrete Mathematics and Quantum Information
(a new specialization!)

Fall 2021: Master Seminar Theoretical Physics

Fall 2021: Web class Quantum Quest [more]

Spring 2021: MasterMath course Quantum Information Theory [more]

Fall 2020: Bachelor’s course Introduction to Information Theory [more]

Fall 2020: Master Seminar Theoretical Physics [more]

Fall 2020: Reading group From Euclidean to Geodesic Convex Optimization [more]

Fall 2020: Web class Quantum Quest [more]

Spring 2020: MasterMath course Quantum Information Theory [more]

Spring 2020: Master Seminar in Algebra, Geometry and Mathematical Physics

Spring 2020: Reading group From Euclidean to Geodesic Convex Optimization [more]

Fall 2019: New Bachelor’s course Introduction to Information Theory [more]

Fall 2019: Master Seminar in Algebra, Geometry and Mathematical Physics [more]
We read Bernd Sturmfels’ book “Algorithms in Invariant Theory”.

Fall 2019: Master Seminar Theoretical Physics [more]

Spring 2019: New MasterMath course Quantum Information Theory [more]

Spring 2019: Master Seminar in Algebra, Geometry and Mathematical Physics [more]
We read Sagan’s book “The Symmetric Group”. Here is a refresher on basic representation theory roughly following Sections 1.1–1.6.

Fall 2018: Web class Quantum Quest [more]

Spring 2018: New Master course on Symmetry and Quantum Information [more]
I previously taught a similar course at Stanford University. Watch this lecture as a teaser. I also taught an abridged version of this course at IES in Cargese.

See here for introductory lectures on quantum information, field theory, and gravity (with an emphasis on links between these fields).

See here and here if you are looking for a Google Summer of Code project!

Quantum Software and Society

Selected Talks

  • “Approximate QCAs and a converse to the Lieb-Robinson bounds”, Banff 2021 [pdf]
  • “Noncommutative Group Symmetries and Optimization”, Oberwolfach 2021 [pdf]
  • “Hidden Symmetries II: Noncommutative Duality, Geodesic Convexity, Polytopes”, Berkeley 2021 [pdf] [video]
  • “Quantum Brascamp-Lieb inequalities”, IPAM 2021 [video], ICMP 2021 [pdf]
  • “Maximum likelihood estimation for tensor normal models”, Firenze 2021
  • “Fun with Replicas & Holographic Tensor Networks”, Perimeter 2020 [video]
  • “Tensors, invariants, and optimization”, Leipzig 2019, Berkeley 2019, Berlin 2020, Chennai 2020, Perimeter 2020 [pdf] [pdf] [pdf] [pdf] [pdf]
  • “Quantum circuits for the Dirac field in 1+1 dimensions”, AEI 2019, Stanford 2019, YITP 2019 [pdf] [video] [pdf] [pdf]
  • “Quantum marginals, invariants, and non-commutative optimization”, Leiden 2019, SIAM-AG 2019 [pdf] [pdf]
  • “Quantum Marginals, Entanglement, and Symmetries”, DPG 2019 [pdf]
  • “An invitation to tensor networks”, IAS 2018 [video]
  • “Quantum Information and Holography”, DESY 2018 [pdf] [video]
  • “Schur-Weyl Duality for the Clifford Group: Property testing, de Finetti representations, and a robust Hudson theorem”, QIP 2018, Boulder 2018, Bad Honnef 2018 [pdf] [video] [pdf] [pdf]
  • “Quantum entanglement and space-time”, Groningen 2018 [html] [video]
  • “Convexity, marginals, and moment polytopes”, IAS 2018 [pdf] [video]
  • “Introduction to Quantum Programming”, QuSoft 2018
  • “Quantum marginal problem, tensor scaling, and invariant theory”, NMC 2018 [pdf]
  • “Rigorous entanglement renormalization from wavelets”, KITP 2017, Caltech 2017, AEI 2018, Amsterdam 2018, GGI 2018 [pdf] [video] [pdf] [pdf] [pdf]
  • “When is a quantum state a stabilizer state?”, QuSoft 2017, QuTech 2018 [pdf]
  • “Bulk reconstruction, error correction, and recovery maps”, KITP 2017 [video]
  • “Tensor network models of holography”, DESY 2017
  • “When is a state a stabilizer state? Testing stabilizer states with six copies”, CWI 2017
  • “Tensors and Quantum Physics”, Auburn 2017 [video]
  • “Multiparty entanglement, random codes, and quantum gravity”, Coogee 2017 [pdf], “Multipartite entanglement in toy models of holography”, Simons Center for Geometry & Physics 2016 [pdf] [video]
  • “Entanglement in random tensor networks”, Georgia Tech 2016 [pdf]
  • “Holographic duality from random tensor networks”, MIT 2015, KITP 2016, Cologne 2016, IQC 2016 [pdf] [pdf] [video] [other]
  • “Moment polytopes & computational complexity”, Berkeley 2015 [pdf]
  • “The Holographic Entropy Cone”, ETHZ, Caltech, CRM 2015; QIP 2016 [pdf short] [video] [pdf long]
  • “Kronecker coefficients and complexity theory”, Dartmouth 2015, Rome 2016 [pdf]
  • “Topologically ordered models in higher dimensions”, QGQIT 2015 [pdf]
  • “Random Quantum Marginals”, IAS 2014 [video]
  • “A Heisenberg Limit for Quantum Region Estimation”, ISIT 2014 [pdf]
  • “The Quantum Marginal Problem”, DPG Spring Meeting 2014 [pdf]
  • “Entanglement Polytopes”, QIP 2013; QSIT Lunch Seminar [pdf] [video] [science] [pdf] [explorer]
  • “Quantum Entropies and Representation Theory”, IHES 2013 [pdf]
  • “Computing Multiplicities of Lie Group Representations”, FOCS 2012 [pdf] [video]
  • “Quantum State Tomography of 1000 Bosons”, SPS Meeting 2012 [pdf]
  • “Quantum Marginals and Classical Moments”, IMS 2013 [pdf]
  • “Eigenvalue Distributions of Reduced Density Matrices”, ICMP 2012 [pdf]