Joshua Foo

I am a theoretical physicist and Banting Postdoctoral Fellow at the University of Waterloo. I was previously a postdoctoral researcher in the group of Igor Pikovski at Stevens Institute of Technology in Hoboken, New Jersey. I completed my PhD, titled "Fundamental Aspects of Quantum Foundations, Field Theory, and Gravity", under the supervision of Prof. Tim Ralph and Dr. Magdalena Zych at the University of Queensland.In my research, I study the foundations of quantum theory and gravity using the tools of atomic physics and quantum optics. Some recent topics of interest include:

  • Probing foundations of relativistic quantum mechanics with quantum optics

  • Testing the interplay of relativistic and quantum effects in atomic platforms

  • Understanding quantum gravity phenomenology with low-energy systems

Beyond research, I am committed to student mentorship and supervision. I am an APS Career Mentoring Fellow and a member of the National Mentoring Community. I have co-supervised a number of undergraduate, Master’s and Ph.D. projects, leading to publications in Physical Review Letters, Classical and Quantum Gravity, and Physical Review D.

  • 29.9.2025: New Scientist published an article about our recent results on witnessing quantum effects in the proper time dynamics of optical clocks.

  • 8.8.2025: Our paper proposing an experiment to witness general relativistic effects in atom interferometry has been published in Quantum. In collaboration with Jerzy Paczos and Magdalena Zych.

  • 9.6.2025: I attended Helgoland 2025, a workshop celebrating the 100th anniversary of Werner Heisenberg's trip to the island and subsequent discovery of matrix mechanics. Quanta magazine published an article covering the event.

  • 2.5.2025: Our paper on general relativistic weak values of photons was published in Physical Review A. In collaboration with Cameron Bellamy and Tim Ralph.

  • 5.3.2025: Our preprint proposing to observe particle production with a quantum metasurface was posted to the arXiv. In collaboration with Germain Tobar, Sofia Qvarfort, Fabio Costa, Rivka Bekenstein, and Magdalena Zych.

  • 27.2.2025: I was awarded the Universe travel award.

  • 23.1.2025: I gave an invited talk at the Peng Huanwu Forum on Theoretical Physics hosted by the Institute of Theoretical Physics in Beijing. I was awarded the Best Presentation Prize.

  • 1.1.2025: I joined the University of Waterloo as a Banting Postdoctoral Fellow. An article about my research was published here.

Academic Positions

  • Jan. 2025 to Present: Banting Postdoctoral Fellow, Department of Physics and Astronomy at University of Waterloo. Independent research fellowship awarded by Natural Sciences and Engineering Research Council of Canada.

  • Apr. 2023 to Dec. 2024: Postdoctoral Researcher, Department of Physics at 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, School of Mathematics and Physics at 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.

25. Quantum signatures of proper time in optical ion clocks, Gabriel Sorci, Joshua Foo, Dietrich Leibfried, Christian Sanner, and Igor Pikovski, arXiv:2509.09573 (2025) .24. General relativistic particle trajectories via quantum-mechanical weak values and the Schwarzschild-Alcubierre metric, Joshua Foo, Cameron Bellamy, Timothy C. Ralph, Phys. Rev. A 111 (2025).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 (2025).22. Witnessing mass-energy equivalence with trapped atom interferometers, Jerzy Paczos, Joshua Foo, and Magdalena Zych, Quantum 9 (2025).21. Superpositions of thermalisations in relativistic quantum field theory, Joshua Foo and Magdalena Zych, Quantum 9 (2025).20. Measurement-based, Lorentz-covariant Bohmian trajectories of multiple photons, Joshua Foo, Austin P. Lund, and Timothy C. Ralph, Phys. Rev. A 108 (2024).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, Phys. Rev. D 110 (2024).18. Mass of a weakly measured photon, Yakov Bloch and Joshua Foo, Phys. Rev. A 108 (2023).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, International Journal of Modern Physics D, 32 (2023).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 (2023).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, Honourable Mention in Gravity Research Foundation Essay Competition, International Journal of Modern Physics D 31 (2022).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)](https://journals.aps.org/prd/abstract/10.1103/PhysRevD.103.065013).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. Project title: Beyond quantum field theory in curved spacetime. In progress (2025-present). Sijia Wang, University of Waterloo. In progress (2025-present).

Service

  • Mentorship: APS Career Mentoring Fellow (2024-Present), Member of APS National Mentoring Community (2024-Present).

  • Journal Refereeing: Physical Review Letters, Physical Review D, 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.

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