Joshua Foo

Theoretical Physicist, Banting Postdoctoral Fellow

About

I am a theoretical physicist working at the intersection of quantum mechanics and gravity. I am currently a Banting Postdoctoral Fellow at the University of Waterloo.Previously, I was a Postdoctoral Fellow in the group of Prof. Igor Pikovski at Stevens Institute of Technology. I completed my PhD, titled "Fundamental Aspects of Quantum Foundations, Field Theory, and Gravity", under the supervision of Prof. Ralph and Dr. Magdalena Zych.

With my daughter in Stockholm, July 2023, for the workshop "Simulating gravity in gedanken and tabletop experiments", co-organised by Igor Pikovski (Stockholm University) and Rivka Bekenstein (Hebrew University of Jerusalem).

Research

My research revolves around aspects of quantum foundations, quantum field theory, general relativity, and quantum optics. I am particularly interested in applying the tools of quantum optics and quantum information to develop theoretical frameworks and experimental proposals to probe the interface of quantum mechanics and gravity. Below is a list of my selected publications.

Academic Positions

  • Jan. 2025 to Present Banting Postdoctoral Fellow, University of Waterloo. Independent research fellowship awarded by National Sciences and Engineering Research Council of Canada. My project is titled "Understanding the quantum physics of spacetime".

  • Apr. 2023 to Dec. 2024 Postdoctoral Fellow, Stevens Institute of Technology. Situated in the group of Igor Pikovski, working on general relativistic effects in atomic clocks and novel approaches to quantum sensing.

  • Oct. 2022 to Mar. 2023 Postdoctoral Researcher, University of Queensland. Situated in the group of Tim Ralph, working on theoretical quantum optics and quantum foundations.

Education

  • Apr. 2019 to Oct. 2022 PhD in Quantum Foundations, Field Theory, and Gravity. Institution: University of Queensland. Thesis title: "Fundamental Aspects of Quantum Foundations, Field Theory, and Gravity". Supervisors: Prof. Tim Ralph and Dr. Magdalena Zych. Recognitions and awards: shortlisted nationally for Bragg Medal for Excellence in Physics (2023), UQ Best Student Publication Prize (2023), Honourable Mentions in Gravity Research Foundation Essay Competition (2022, 2023).

  • Apr. 2015 to Dec. 2018 Bachelor of Advanced Science (Honours Class I). Institution: University of Queensland. Thesis title: "Generating Negative Energy Densities with an Accelerated Quantum Teleporter". Supervisor: Prof. Tim Ralph. Recognitions and awards: Dean's Commendation (2015-2018), Undergraduate Physics Prize (2017), UCEAP Award for Study Abroad Semester at U.C. Berkeley (2016). Research projects: "Chaotic dynamics of a Bose-Einstein condensate in a double-well potential", w. Prof. Joel Corney, "Detection of a quantum spin liquid via Raman scattering", w. Prof. Ben Powell.

Publications

An up-to-date list of my publications can be found on Google Scholar.

23. Quantum metasurfaces as probes of vacuum particle content, Germain Tobar, Joshua Foo, Sofia Qvarfort, Fabio Costa, Rivka Bekenstein, and Magdalena Zych, arXiv:2503.03838.22. Witnessing mass-energy equivalence with trapped atom interferometers, Jerzy Paczos, Joshua Foo, and Magdalena Zych, arXiv:2406.19037.21. Measurement-based, Lorentz-covariant Bohmian trajectories of multiple photons, Joshua Foo, Austin P. Lund, and Timothy C. Ralph, Phys. Rev. A 108 (2023).20. Mass of a weakly measured photon, Yakov Bloch and Joshua Foo, Phys. Rev. A 108 (2023).19. Signatures of rotating black holes in quantum superposition, C. Suuryatmadja, C.S. Arabaci, M.P.G. Robbins, Joshua Foo, Magdalena Zych, and Robert B. Mann, arXiv:2310.10864.18. Superpositions of thermalisations in relativistic quantum field theory, Joshua Foo and Magdalena Zych, Quantum 9, 1629 (2025).17. Signatures of discretization in quantum black hole spectra, Joshua Foo, Magdelena Zych, and Robert B. Mann, Honourable Mention in Gravity Research Foundation Essay Competition.16. Quantum superpositions of Minkowski spacetime, Joshua Foo, Cemile Senem Arabaci, Magdalena Zych, and Robert B. Mann, Phys. Rev. D 107 (2023).15. Relativity and decoherence of spacetime superpositions, Joshua Foo, Robert B. Mann, and Magdalena Zych, arXiv:2302.03259.14. Quantum signatures of black hole mass superpositions, Joshua Foo, Cecile Senem Arabaci, Magdalena Zych, and Robert B. Mann, Phys. Rev. Lett 129 (2022).13. Relativistic Bohmian trajectories of photons via weak measurements, Joshua Foo, Estelle Asmodelle, Austin P. Lund, and Timothy C. Ralph, Nature Communications 13 (2022).12. Schrodinger's black hole cat, Joshua Foo, Robert B. Mann, and Magdalena Zych, International Journal of Modern Physics D 31 (2022). Honourable Mention in Gravity Research Foundation Essay Competition.11. Telefilters, telemirrors, and causality, Joshua Foo, Sho Onoe, Magdalena Zych, and Timothy C. Ralph, Phys. Rev. A 105 (2022).10. On the duality of Schwarzshild-de Sitter spacetime and moving mirror, Diego Silvestre-Fernandez, Joshua Foo, and Michael R.R. Good, Classical and Quantum Gravity 39 (2022).9. Analog particle production model for general classes of Taub-NUT black holes, Joshua Foo, Michael R.R. Good, and Robert B. Mann, Universe 7 (2021).8. Accelerating boundary analog of a Kerr black hole, Michael R.R. Good, Joshua Foo, and Eric V. Linder, Classical and Quantum Gravity 38 (2021).7. Hawking radiation particle spectrum of a Kerr-Newman black hole, Joshua Foo and Michael R.R. Good, JCAP 19 (2021).6. Entanglement amplification between superposed detectors in flat and curved spacetimes, Joshua Foo, Robert B. Mann, and Magdalena Zych, Phys. Rev. D 103 (2021).5. Schrodinger's cat for de Sitter spacetime, Joshua Foo, Robert B. Mann, and Magdalena Zych, Classical and Quantum Gravity 38 (2020).4. Thermality, causality, and the quantum-controlled Unruh-deWitt detector, Joshua Foo, Sho Onoe, Robert B. Mann, and Magdalena Zych, Phys. Rev. Res. 3 (2020).3. Generating multi-partite vacuum entanglement with a finite-lifetime mirror, Joshua Foo, Sho Onoe, Magdalena Zych, and Timothy C. Ralph, New Journal of Physics 22 (2020).2. Continuous-variable quantum teleportation with vacuum-entangled Rindler modes, Joshua Foo and Timothy C. Ralph, Phys. Rev. D 101 (2020).1. Unruh-deWitt detectors in quantum superpositions of trajectories, Joshua Foo, Sho Onoe, and Magdalena Zych, Phys. Rev. D 102 (2020).

Research Supervision

  • Undergraduate & Honours Students: Alex Tremayne, University of Queensland. Thesis title: "Quantum fields near evaporating black holes" (2023). Gabriel Sorci, Stevens Institute of Technology (2023-present). Finian Casey, University of Queensland. Project title: "Relativistic Bohmian mechanics beyond the optics approximation".

  • Masters Students: Cemile Senem Arabaci, University of Waterloo. Thesis title: "Studying black holes in superposition using Unruh-deWitt particle detectors" (2022). Yakov Bloch, Bar-Ilan University. Project title: "Mass of a weakly measured photon" (2023). Cameron Bellamy, University of Queensland. Project title: "General relativistic photon trajectories via quantum-mechanical weak values and the Schwarzschild-Alcubierre metric" (2024). Ziqi Xu, University of Waterloo. In progress (2025-present). Taylor Cey, University of Waterloo. In progress (2025-present).

  • Ph.D Students: Cendikiawan Suryaatmadja, University of Waterloo. In progress (2023-present). Thomas Abello, Stevens Institute of Technology. In progress (2023-present). Achintya Sajeendran, University of Queensland. In progress (2025-present).

Journal Refereeing

  • Physical Review Letters, Physical Review A, New Journal of Physics, Classical and Quantum Gravity, Proceedings of the Royal Society A, Communications Physics, Quantum, Journal of Physics A: Mathematical and Theoretical, Entropy, Universe, Symmetry.

Contact

Thank you for visiting my website. You can contact me at [email protected]