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- Ravi Kunjwal

Université Libre de Bruxelles (ULB)

Area of Research:

August 2010 - August 2016: The Institute of Mathematical Sciences, Chennai

I work on quantum foundations, primarily from the perspective of quantum information. Much of my research has been devoted to characterizing the nonclassicality that quantum theory allows, and the nonclassicality it forbids. This requires, firstly, a notion of classicality, relative to which one can judge the nonclassicality of quantum theory. Further, for this notion of classicality to be widely applicable and experimentally testable, it should make minimal assumptions about the theoretical model -- quantum or otherwise -- that describes an experiment, and it should be able to handle real-world experiments that do not always satisfy the idealizations presumed in a theoretical model, e.g., the idealization that measurements in a quantum experiment are all projective. The notion of nonclassicality I have been spending a lot of time thinking about is called contextuality and it satisfies many of these features when appropriately operationalized from its origins in the Kochen-Specker theorem. Quite a lot of my research has been about obtaining noise-robust noncontextuality inequalities whose experimental violation can witness contextuality, thereby certifying that the experiment has met a stringent criterion for nonclassicality under very minimal assumptions about the theoretical model describing the experiment. In particular, violation of these inequalities can benchmark the quantumness of an experiment, where ``quantumness" is understood as a departure from classicality, i.e., nonclassicality of quantum theory.

I have also been interested in the interplay of contextuality with two other notions of nonclassicality: Bell nonlocality and the incompatibility of observables. In particular, Bell inequality violations witness a strong form of nonclassicality akin to contextuality, and both of these notions of nonclassicality require incompatibility of measurements and/or incompatibility between preparations.

- 2012 - 2016, The Institute of Mathematical Sciences, Chennai, India, as a Senior Research Fellow, pursuing Ph.D. in Theoretical Physics.
- Fall semesters of 2013-2015, Visiting Graduate Fellow, Perimeter Institute for Theoretical Physics, Canada
- 2010 - 2012, The Institute of Mathematical Sciences, Chennai, India, as a Junior Research Fellow, pursuing M.Sc. in Theoretical Physics.

- Nishi Kant Essay Prize, St. Stephen's College, 2009-2010.
- KPMG Scholarship, St. Stephen's College, 2009-2010.
- Tushar Nagia Stephanian Prize, St. Stephen's College, 2009-2010.
- INSPIRE Scholarship for Higher Education, Department of Science and Technology, Government of India, 2007-2010.

- T. Gonda, R. Kunjwal, D. Schmid, E. Wolfe, and A. B. Sainz, Almost Quantum Correlations are Inconsistent with Specker"s Principle, Quantum 2, 87 (2018).
- R. Kunjwal and R. W. Spekkens, From statistical proofs of the Kochen-Specker theorem to noise-robust noncontextuality inequalities, Phys. Rev. A 97, 052110 (2018).
- M.D. Mazurek, M. F. Pusey, R. Kunjwal, K. J. Resch and R.W. Spekkens, An experimental test of noncontextuality without unphysical idealizations, Nature Communications 7:11780 (2016), arXiv: 1505.06244 (2015).
- R. Kunjwal and R. W. Spekkens, From the Kochen-Specker theorem to noncontextuality inequalities without assuming determinism, Phys. Rev. Lett. 115, 110403 (2015), arXiv: 1506.04150 (2015).
- R. Kunjwal, Fine's theorem, noncontextuality, and correlations in Specker's scenario, Phys. Rev. A 91, 022108 (2015), arXiv: 1410.7760 (2014).
- R. Kunjwal, C. Heunen, and T. Fritz, Quantum realization of arbitrary joint measurability structures, Phys. Rev. A 89, 052126 (2014), arXiv: 1311.5948 (2013).
- R. Kunjwal and S. Ghosh, Minimal state-dependent proof of measurement contextuality for a qubit, Phys. Rev. A 89, 042118 (2014), arXiv: 1305.7009 (2013).
- R. Singh, R. Kunjwal, and R. Simon, Relative volume of separable bipartite states, Phys. Rev. A 89, 022308 (2014), arXiv: 1307.1454 (2013).
- Bell Quantified: The Resource Theory of Nonclassicality of Common-Cause Boxes, E. Wolfe, D. Schmid, A. B. Sainz, R. Kunjwal, and R. W. Spekkens, arXiv: 1903.06311 [quant-ph] (2018)
- Anomalous weak values and contextuality: robustness, tightness, and imaginary parts, R. Kunjwal, M. Lostaglio, and M.F. Pusey, arXiv: 1812.06940 [quant-ph] (2018)
- Hypergraph framework for irreducible noncontextuality inequalities from logical proofs of the Kochen-Specker theorem, R. Kunjwal, arXiv: 1805.02083 [quant-ph] (2018)
- Beyond the Cabello-Severini-Winter framework: making sense of contextuality without sharpness of measurements, Ravi Kunjwal, arXiv: 1709.01098 [quant-ph] (2017)
- Contextuality beyond the Kochen-Specker theorem (PhD thesis), R. Kunjwal, arXiv: 1612.07250 [quant-ph] (2016)
- A note on the joint measurability of POVMs and its implications for contextuality, R. Kunjwal, arXiv: 1403.0470 [quant-ph] (2014)

- Bell Quantified: The Resource Theory of Nonclassicality of Common-Cause Boxes, on July 10, 2019, at Quantum Causal Structures (QCS), University of Oxford, UK.
- Anomalous weak values and contextuality: robustness, tightness, and imaginary parts, on June 13, 2019, at QPL 2019, Chapman University, Orange, California, USA.
- Noise-robust contextuality for Kochen-Specker type scenarios: two complementary frameworks, on April 9, 2019, at Robert Raussendorf"s group meeting at University of British Columbia, Vancouver, Canada.
- Noise-robust contextuality for Kochen-Specker type scenarios: two complementary frameworks, on March 21, 2019, at the PIMan Workshop, Orange, California, USA.
- Experimentally robust nonclassicality, on December 21, 2018, at the International Centre for Theoretical Sciences (ICTS), Bengaluru, India.
- Hypergraph framework for Spekkens contextuality applied to Kochen-Specker scenarios, on December 18, 2018, at IMSc, Chennai, India.
- Hypergraph framework(s) for Spekkens contextuality applied to Kochen-Specker scenarios, on November 29, 2018, at Q-Turn, Florianopolis, Brazil.
- Contextuality attenuates noise in classical communication, on October 22, 2018, âLobster Lunch" talk (Jon Barrett's group meeting) at the Quantum Group, Department of Computer Science, University of Oxford, UK.
- Hypergraph framework for Spekkens contextuality applied to Kochen-Specker scenarios, on June 18, 2018, at University College London, London, UK.
- Beyond the CSW framework: a hypergraph framework for Spekkens contextuality, on June 17, 2018, at Quantum Physics and Logic (QPL), 2018, Dalhousie University, Halifax, Canada.
- Resource theory of the nonclassicality of common-cause boxes, on June 13, 2018, at the JTF Quantum Causality workshop, University of Oxford, Oxford, UK.
- How to go from the Kochen-Specker theorem to experimentally testable signatures of contextuality, on March 22, 2018, at the QuICS Seminar, University of Maryland, College Park, MD, USA.
- Contextuality as a noise-robust witness of nonclassicality: beyond the Cabello-Severini-Winter framework, on March 8, 2018, at the APS March Meeting, Quantum Foundations Session II, Los Angeles, USA.
- Noise-robust noncontextuality inequalities from the Kochen-Specker theorem, on March 2, 2018, at the Aharanov-Albert-Vaidman (AAV) Anniversary Conference, Chapman University, Orange County, USA.
- How to go from the Kochen-Specker theorem to experimentally testable signatures of contextuality, on January 19, 2018, at the Raman Research Institute (RRI), Bengaluru, India
- Witnessing nonclassicality from statistical proofs of the Kochen-Specker theorem, on January 17, 2018, at the Tata Institute of Fundamental Research (TIFR), Mumbai, India
- A hypergraph framework for Spekkens contextuality applied to statistical proofs of the Kochen-Specker theorem, on January 9, 2018, at the Indian Institute of Science Education and Research (IISER), Mohali, India.
- From statistical proofs of the Kochen-Specker theorem to noise-robust noncontextuality inequalities, on December 20, 2017, at the Institute of Mathematical Sciences (IMSc), Chennai, India.
- Irreducible noncontextuality inequalities from the Kochen-Specker theorem, Contributed talk, at the Conference on Quantum Information and Quantum Control VII (CQIQC-VII), 2017, at Fields Institute, Toronto, Canada.
- How to go from the Kochen-Specker theorem to experimentally testable noncontextuality inequalities, on July 18, 2017, at the University of Queensland, Brisbane, Australia.
- Irreducible noncontextuality inequalities from the Kochen-Specker theorem, on July 6, 2017, at Quantum Physics and Logic (QPL), 2017, Nijmegen, The Netherlands.
- Irreducible noncontextuality inequalities from the Kochen-Specker theorem, on June 14, 2017, at the Group of Applied Physics, University of Geneva, Geneva, Switzerland.
- A road to contextuality via Specker's parable, on June 8, 2017, at University of Turku, Turku, Finland.
- Irreducible noncontextuality inequalities from the Kochen-Specker theorem, on June 4, 2017, at Quantum Contextuality in Quantum Mechanics and Beyond (QCQMB), Prague, Czech Republic.
- Irreducible noncontextuality inequalities from the Kochen-Specker theorem, on May 31, 2017, at Universitat Autonoma Barcelona (UAB), Bellaterra (Barcelona), Spain.
- Irreducible noncontextuality inequalities from the Kochen-Specker theorem, on May 30, 2017, at The Institute of Photonic Sciences (ICFO), Castelldefels (Barcelona), Spain.
- What are the simplest noncontextuality inequalities obtainable from KS-uncolourable hypergraphs?, on December 29, 2016, at The Institute of Mathematical Sciences (IMSc), Chennai, India.
- Contextuality in the presence of noise, on December 19, 2016, at the Random Interactions seminar at Tata Institute of Fundamental Research (TIFR), Mumbai, India.
- Noncontextuality inequalities for Specker's compatibility scenario and beyond, on June 8, 2016, at Quantum Physics and Logic (QPL), 2016, University of Strathclyde, Glasgow, Scotland (UK).
- From the Kochen-Specker theorem to noncontextuality inequalities without assuming determinism, Quantum Physics and Logic (QPL) 2015, on July 15, 2015, at the University of Oxford, Oxford, England (UK).
- Fine's theorem, noncontextuality, and correlations in Specker's scenario, on February 24, 2015, at Young Quantum 2015, Harish-Chandra Research Institute (HRI), Allahabad, India.
- Minimal state-dependent proof of measurement contextuality for a qubit, Short talk, on August 27, 2013, at the 13th Asian Quantum Information Science Conference (AQIS) 2013, at the Institute of Mathematical Sciences (IMSc), Chennai, India.
- PIRSA:17070059, How to go from the KS theorem to experimentally testable noncontextuality inequalities, 2017-07-28, Contextuality: Conceptual Issues, Operational Signatures, and Applications
- PIRSA:14010102, Noncontextuality without determinism and admissible (in)compatibility relations: revisiting Specker's parable, 2014-01-14, Quantum Foundations

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