# Robert Spekkens

Perimeter Institute for Theoretical Physics

Areas of research:

### Overview

Robert Spekkens received his B.Sc. in physics and philosophy from McGill University and completed his M.Sc. and Ph.D. in Physics at the University of Toronto. He held a postdoctoral fellowship at Perimeter Institute and an International Royal Society Fellowship at the University of Cambridge. He has been a faculty member at Perimeter Institute since November 2008. His research is focused upon identifying the conceptual innovations that distinguish quantum theories from classical theories and investigating their significance for axiomatization, interpretation, and the implementation of various information-theoretic tasks.

### Teaching Affiliations

If you are interested in working with me as a PhD student, please send me an email at [email protected]. Perimeter Institute is committed to diversity within its community and I welcome applications from underrepresented groups.

### Research Interests

E. T. Jaynes famously described quantum theory as an omelette of epistemological and ontological elements, all scrambled up in a way that no one has yet seen how to unscramble. One of the central aims of my research is to unscramble the quantum omelette. In recent years I have been focussed upon distinguishing causation from correlation in the quantum formalism, that is, influence from inference. In particular, I have been developing the concepts of quantum Bayesian inference and quantum causal models, as well as their applications for inferring causal structure from observed correlations. This framework provides a novel perspective on the topics of locality and noncontextuality in quantum theory. I also work on quantum resource theories, where various properties of quantum states and operations are formalized as resources.

### Positions Held

- Adjunct research faculty, Centre for Quantum Dynamics, Griffith University, 2010-2016
- Junior Research Faculty, Perimeter Institute for Theoretical Physics, 2008-2015
- Adjunct faculty, Department of Physics and Astronomy, University of Waterloo, 2008-present
- Royal Society International Research Fellow, University of Cambridge, 2006-2008
- Postdoctoral Researcher, Perimeter Institute for Theoretical Physics, 2003-2006
- Postdoctoral Researcher, Department of Physics, University of Toronto, 2001-2002

### Awards

- The Itamar Pitowsky Memorial Lecture, Hebrew University of Jerusalem, 2017
- Discovery Grant "Strong notions of nonclassicality: experimental signatures and applications", Natural Sciences and Engineering Research Council of Canada (NSERC), 2017-2022
- FQXI Essay Contest, 1st prize, FQXI, 2012
- Paper selected by editors of NJP for IOP Select, New Journal of Physics, 2009
- Article highlighted as an Editor's Suggestion, Physical Review Letters, 2008
- Paper award, "Best of 2008", New Journal of Physics, 2008
- Birkhoff-von Neumann Prize, International Quantum Structures Association, 2008

### Recent Publications

- Schmid, D., Selby, J. H., Pusey, M. F., & Spekkens, R. W. (n.d.). A structure theorem for generalized-noncontextual ontological models. Quantum, 8, 1283. doi:10.22331/q-2024-03-14-1283
- Schmid, D., Selby, J. H., & Spekkens, R. W. (2024). Addressing some common objections to generalized noncontextuality. Physical Review A, 109(2), 022228. doi:10.1103/physreva.109.022228
- Schmid, D., Fraser, T. C., Kunjwal, R., Sainz, A. B., Wolfe, E., & Spekkens, R. W. (n.d.). Understanding the interplay of entanglement and nonlocality: motivating and developing a new branch of entanglement theory. Quantum, 7, 1194. doi:10.22331/q-2023-12-04-1194
- Catani, L., Leifer, M., Schmid, D., & Spekkens, R. W. (n.d.). Why interference phenomena do not capture the essence of quantum theory. Quantum, 7, 1119. doi:10.22331/q-2023-09-25-1119
- Gonda, T., & Spekkens, R. W. (n.d.). Monotones in General Resource Theories. Compositionality, 5, 7. doi:10.32408/compositionality-5-7
- Catani, L., Leifer, M., Scala, G., Schmid, D., & Spekkens, R. W. (2023). Aspects of the phenomenology of interference that are genuinely nonclassical. Physical Review A, 108(2), 022207. doi:10.1103/physreva.108.022207
- Selby, J. H., Schmid, D., Wolfe, E., Sainz, A. B., Kunjwal, R., & Spekkens, R. W. (2023). Contextuality without Incompatibility. Physical Review Letters, 130(23), 230201. doi:10.1103/physrevlett.130.230201
- Selby, J. H., Schmid, D., Wolfe, E., Sainz, A. B., Kunjwal, R., & Spekkens, R. W. (2023). Accessible fragments of generalized probabilistic theories, cone equivalence, and applications to witnessing nonclassicality. Physical Review A, 107(6), 062203. doi:10.1103/physreva.107.062203
- Polino, E., Poderini, D., Rodari, G., Agresti, I., Suprano, A., Carvacho, G., . . . Sciarrino, F. (n.d.). Experimental nonclassicality in a causal network without assuming freedom of choice. Nature Communications, 14(1), 909. doi:10.1038/s41467-023-36428-w
- Schmid, D., Selby, J. H., & Spekkens, R. W. (2023). Addressing some common objections to generalized noncontextuality. arxiv:2302.07282v2
- Suprano, A., Polino, E., Poderini, D., Rodari, G., Agresti, I., Milani, G., . . . Sciarrino, F. (n.d.). Nonlocality detection in photonic triangle networks. In CLEO 2023 (pp. ff3a.2). Optica Publishing Group. doi:10.1364/cleo_fs.2023.ff3a.2
- Catani, L., Leifer, M., Scala, G., Schmid, D., & Spekkens, R. W. (2022). What is Nonclassical about Uncertainty Relations?. Physical Review Letters, 129(24), 240401. doi:10.1103/physrevlett.129.240401
- Catani, L., Leifer, M., Schmid, D., & Spekkens, R. W. (2022). Reply to "Comment on 'Why interference phenomena do not capture the essence of quantum theory' ". doi:10.48550/arxiv.2207.11791
- Daley, P. J., Resch, K. J., & Spekkens, R. W. (2022). Experimentally adjudicating between different causal accounts of Bell-inequality violations via statistical model selection. Physical Review A, 105(4), 042220. doi:10.1103/physreva.105.042220
- Grabowecky, M. J., Pollack, C. A. J., Cameron, A. R., Spekkens, R. W., & Resch, K. J. (2022). Experimentally bounding deviations from quantum theory for a photonic three-level system using theory-agnostic tomography. Physical Review A, 105(3), 032204. doi:10.1103/physreva.105.032204
- Chaves, R., Moreno, G., Polino, E., Poderini, D., Agresti, I., Suprano, A., . . . Sciarrino, F. (2021). Causal Networks and Freedom of Choice in Bell’s Theorem. PRX Quantum, 2(4), 040323. doi:10.1103/prxquantum.2.040323
- Zjawin, B., Wolfe, E., & Spekkens, R. W. (n.d.). Restricted Hidden Cardinality Constraints in Causal Models. Electronic Proceedings in Theoretical Computer Science, 343, 119-131. doi:10.4204/eptcs.343.6
- Zjawin, B., Wolfe, E., & Spekkens, R. W. (2021). Restricted Hidden Cardinality Constraints in Causal Models. doi:10.48550/arxiv.2109.05656
- Finkelstein, N., Zjawin, B., Wolfe, E., Shpitser, I., & Spekkens, R. W. (2021). Entropic Inequality Constraints from $e$-separation Relations in Directed Acyclic Graphs with Hidden Variables. doi:10.48550/arxiv.2107.07087
- Mazurek, M. D., Pusey, M. F., Resch, K. J., & Spekkens, R. W. (2021). Experimentally Bounding Deviations From Quantum Theory in the Landscape of Generalized Probabilistic Theories. PRX Quantum, 2(2). doi:10.1103/prxquantum.2.020302
- Schmid, D., Selby, J. H., Wolfe, E., Kunjwal, R., & Spekkens, R. W. (2021). Characterization of Noncontextuality in the Framework of Generalized Probabilistic Theories. PRX Quantum, 2(1). doi:10.1103/prxquantum.2.010331

### Seminars

- Quantum Foundations meets Causal Inference, ICTQT, University of Gdansk, Gdansk, Poland, 2023/05/31
- Unscrambling the omelette of causation and inference in quantum theory, New Directions in the Foundations of Physics, Viterbo, Italy, 2023/05/27
- Tutorial 1, Causal Inference & Quantum Foundations Workshop, 2023/04/17, PIRSA:23040103
- Causal Inference Lecture - 230412, Causal Inference: Classical and Quantum, 2023/04/12, PIRSA:23040003
- Causal Inference Lecture - 230405, Causal Inference: Classical and Quantum, 2023/04/05, PIRSA:23040001
- Causal Inference Lecture - 230403, Causal Inference: Classical and Quantum, 2023/04/03, PIRSA:23040000
- Causal Inference Lecture - 230322, Causal Inference: Classical and Quantum, 2023/03/22, PIRSA:23030074
- Causal Inference Lecture - 230320, Causal Inference: Classical and Quantum, 2023/03/20, PIRSA:23030073
- Causal Inference Lecture - 230315, Causal Inference: Classical and Quantum, 2023/03/15, PIRSA:23030072
- Causal Inference Lecture - 230313, Causal Inference: Classical and Quantum, 2023/03/13, PIRSA:23030071
- Causal Inference Lecture - 230308, Causal Inference: Classical and Quantum, 2023/03/08, PIRSA:23030070
- Causal Inference Lecture - 230306, Causal Inference: Classical and Quantum, 2023/03/06, PIRSA:23030069
- Quantum Foundations Meets Causal Inference, Duke University, Durham, United States, 2022/11/02
- Tips for giving a great talk, , 2022/10/17, PIRSA:22100109
- Why interference phenomena do not capture the essence of quantum theory, Quantum Information and Quantum Control IX, University of Toronto, Toronto, ON, Canada, 2022/01/01
- Time Symmetry in Quantum Theory, Quantum Information Structure of SpaceTime (QISS) Conference, Western University, London, ON, Canada, 2022/01/01
- Quantum Foundations Meets Causal Inference, Canadian Association of Physicists (CAP) Conference, McMaster University, Hamilton, ON, Canada, 2022/01/01
- Quantum Foundations Meets Causal Inference, International Conference on Quantum Information and Foundations (ICQIF-2022), Kolkata, India, 2022/01/01
- Adjudicating Between Different Causal Accounts of Bell Inequality Violations, Quantum Physics and Statistical Causal Models, Simons Institute, Berkeley, California, 2022/01/01
- Quantizing causation, Quantizing Time, 2021/06/14, PIRSA:21060089