Associate Professor Jacqui Romero

Associate Professor

School of Mathematics and Physics
Faculty of Science

Affiliate of ARC COE for Engineered

ARC Centre of Excellence for Engineered Quantum Systems
Faculty of Science
+61 7 334 67031


Dr Jacqui Romero is an expert in experimental quantum information. Her research is focused on using higher-dimensional systems for exploring curious quantum physics phenomena and developing future quantum technologies. She is the group leader of the research team Qudits@UQ, there's more information on her group's webpage.

Jacqui was born and bred in Manila, Philippines. Hearing her high school physics teacher complain about quantum physics, she became curious and googled "quantum physics"—she has been hooked ever since. She holds BS Applied Physics magna cum laude and MS Physics degrees from the University of the Philippines. She finished her PhD at the University of Glasgow (in sunny Scotland!) where she was a researcher for seven years. In 2015, she moved to Brisbane to join the Quantum Technology group at the University of Queensland. In 2016 she took up an ARC DECRA fellowship with the same group. In 2019, she took up a Westpac Research Fellowship and formed her own team, Qudits@UQ. Jacqui is recognised for moving the shape of photons to mainstream quantum information. She has received several prestigious national and international awards which include: a L'Oreal-UNESCO For Women In Science award in 2017 (one of four in Australia), the Ruby Payne-Scott Medal of the Australian Institute of Physics for excellence in early-career research in 2018, and a L'Oreal-UNESCO For Women In Science International Rising Talent Award in 2019 (one of fifteen awards globally).

She is currently an associate professor and Westpac Research Fellow. She is also a chief investigator at the Centre of Excellence For Engineered Quantum Systems (EQUS).

Outside work, she is a busy mum to three lovely boys, and an occasional painter. She also loves sharing her research to the wider community, example here.

Research Interests

  • Generating high-dimensional quantum states
    Quantum information and quantum technologies are largely based on qubits—two-dimensional quantum systems that is the quantum counterpart of the classical bit. Given that quantum systems are naturally high-dimensional, the restriction to qubits is not necessary. Nature provides us with qudits—d-level quantum systems—which we could use to represent quantum information. Using qudits comes with immediate benefits like higher information capacity, and robustness to noise. Entanglement—the quintessential quantum phenomenon that allows stronger-than-classical correlations—is far richer offers more advantages in higher dimensions. We are interested in experimentally generating high-dimensional quantum states (entangled or otherwise!) for quantum communication and quantum computation by controlling the various properties of the photon.
  • High-dimensional quantum information processing
    Manipulating photonic high-dimensional quantum information becomes challenging both in scale and control as the qudit dimension increases. We are interested in designing devices (whether in free space or on-chip) that are both efficient and high-fidelity via inverse design. Here, the desired outputs and inputs are specified and the device is found either by computational search and optimisation, or by using good old optics!
  • Tools for characterising high-dimensional quantum information
    As the space for quantum information increases, so does the difficulty of characterising of quantum states and quantum processes. For example, the parameter space for qudits grows as ~d^(2n), where d is the qudit dimension and n is the number of particles. We are interested in methods that scale more favourably with dimension, either by requiring fewer measurements or by being more computationally efficient.
  • Higher-order maps
    Higher-order maps act on quantum processes, rather than quantum states. Higher-order maps open more possibilities, one example is indefinite causal order, wherein the order of events are not definite (think of chicken and egg---both could come first!). We are interested in demonstrating new capabilities and advantages afforded by these higher-order maps for improving quantum communication and quantum computation.
  • Quantum error correction and noise mitigation
    Quantum information often needs to be protected from noise in order to be useful. One approach is to encode quantum information in a higher-dimensional quantum system, as in quantum error correction. Correcting for any arbitrary error is extremely challenging. One way to make quantum error correction more manageable is to understand the noise affecting the quantum system and tailor highly optimised protocols based on these noise characteristics. We are interested in using high-dimensional quantum systems to test quantum error correction and noise mitigation protocols.


  • Doctor of Philosophy, University of Glasgow
  • Masters (Coursework) of Physics, University of the Philippines Diliman
  • Bachelor of Applied Physics, University of the Philippines Diliman


View all Publications


View all Grants


View all Supervision


Journal Article

  • Cacciapuoti, Angela Sara, Broadbent, Anne, Diamanti, Eleni, Romero, Jacquiline and Wehner, Stephanie (2024). Guest Editorial The Quantum Internet: Principles, Protocols and Architectures. IEEE Journal on Selected Areas in Communications, 42 (7), 1719-1722. doi: 10.1109/jsac.2024.3379106

  • Ma, Zhonghua, Rambach, Markus, Goswami, Kaumudibikash, Bhattacharya, Some Sankar, Banik, Manik and Romero, Jacquiline (2023). Randomness-free test of nonclassicality: a proof of concept. Physical Review Letters, 131 (13) 130201, 1-7. doi: 10.1103/physrevlett.131.130201

  • Ouyang, Yingkai, Goswami, Kaumudibikash, Romero, Jacquiline, Sanders, Barry C., Hsieh, Min-Hsiu and Tomamichel, Marco (2023). Approximate reconstructability of quantum states and noisy quantum secret sharing schemes. Physical Review A, 108 (1) 012425. doi: 10.1103/PhysRevA.108.012425

  • Rambach, Markus, Youssry, Akram, Tomamichel, Marco and Romero, Jacquiline (2022). Efficient Quantum State Tracking in Noisy Environments. Quantum Science and Technology, 8 (1) 015010, 1-9. doi: 10.1088/2058-9565/aca049

  • Moody, Galan, Sorger, Volker J., Blumenthal, Daniel J., Juodawlkis, Paul W., Loh, William, Sorace-Agaskar, Cheryl, Jones, Alex E., Balram, Krishna C., Matthews, Jonathan C. F., Laing, Anthony, Davanco, Marcelo, Chang, Lin, Bowers, John E., Quack, Niels, Galland, Christophe, Aharonovich, Igor, Wolff, Martin A., Schuck, Carsten, Sinclair, Neil, Lončar, Marko, Komljenovic, Tin, Weld, David, Mookherjea, Shayan, Buckley, Sonia, Radulaski, Marina, Reitzenstein, Stephan, Pingault, Benjamin, Machielse, Bartholomeus, Mukhopadhyay, Debsuvra ... Camacho, Ryan M. (2022). 2022 roadmap on integrated quantum photonics. Journal of Physics: Photonics, 4 (1) 012501, 012501. doi: 10.1088/2515-7647/ac1ef4

  • Romero, Jacquiline and Rambach, Markus (2022). Entanglement levels up. Optics and Photonics News, 33 (1), 32-39. doi: 10.1364/opn.33.1.000032

  • Goswami, K., Giarmatzi, C., Monterola, C., Shrapnel, S., Romero, J. and Costa, F. (2021). Experimental characterization of a non-Markovian quantum process. Physical Review A, 104 (2) 022432. doi: 10.1103/physreva.104.022432

  • Rambach, Markus, Qaryan, Mahdi, Kewming, Michael, Ferrie, Christopher, White, Andrew G. and Romero, Jacquiline (2021). Robust and efficient high-dimensional quantum state tomography. Physical Review Letters, 126 (10) 100402, 100402. doi: 10.1103/physrevlett.126.100402

  • Goswami, K. and Romero, J. (2020). Experiments on quantum causality. AVS Quantum Science, 2 (3) 037101, 037101. doi: 10.1116/5.0010747

  • Goswami, K., Cao, Y., Paz-Silva, G. A., Romero, J. and White, A. G. (2020). Increasing communication capacity via superposition of order. Physical Review Research, 2 (3) 033292. doi: 10.1103/physrevresearch.2.033292

  • Kewming, M. J., Shrapnel, S., White, A. G. and Romero, J. (2020). Hiding ignorance using high dimensions. Physical Review Letters, 124 (25) 250401, 250401. doi: 10.1103/physrevlett.124.250401

  • Cao, Huan, Gao, She-Cheng, Zhang, Chao, Wang, Jian, He, De-Yong, Liu, Bi-Heng, Zhou, Zheng-Wei, Chen, Yu-Jie, Li, Zhao-Hui, Yu, Si-Yuan, Romero, Jacquiline, Huang, Yun-Feng, Li, Chuan-Feng and Guo, Guang-Can (2020). Distribution of high-dimensional orbital angular momentum entanglement over a 1 km few-mode fiber. Optica, 7 (3), 232-237. doi: 10.1364/OPTICA.381403

  • Romero, Jacq (2019). Shaping up high-dimensional quantum information. Australian Physics, 56 (4), 84-86.

  • Goswami, K., Giarmatzi, C., Kewming, M., Costa, F., Branciard, C., Romero, J. and White, A. G. (2018). Indefinite causal order in a quantum switch. Physical Review Letters, 121 (9) 090503, 090503. doi: 10.1103/physrevlett.121.090503

  • Rubinsztein-Dunlop, Halina, Forbes, Andrew, Berry, M. V., Dennis, M. R., Andrews, David L., Mansuripur, Masud, Denz, Cornelia, Alpmann, Christina, Banzer, Peter, Bauer, Thomas, Karimi, Ebrahim, Marrucci, Lorenzo, Padgett, Miles, Ritsch-Marte, Monika, Litchinitser, Natalia M., Bigelow, Nicholas P., Rosales-Guzman, C., Belmonte, A., Torres, J. P., Neely, Tyler W., Baker, Mark, Gordon, Reuven, Stilgoe, Alexander B., Romero, Jacquiline, White, Andrew G., Fickler, Robert, Willner, Alan E., Xie, Guodong, McMorran, Benjamin and Weiner, Andrew M. (2017). Roadmap on structured light. Journal of Optics, 19 (1) 013001, 013001. doi: 10.1088/2040-8978/19/1/013001

  • Roger, Thomas, Restuccia, Sara, Lyons, Ashley, Giovannini, Daniel, Romero, Jacquiline, Jeffers, John, Padgett, Miles and Faccio, Daniele (2016). Coherent absorption of N00N states. Physical Review Letters, 117 (2) 023601, 57-62. doi: 10.1103/PhysRevLett.117.023601

  • Cai, Yu, Bancal, Jean-Daniel, Romero, Jacquiline and Scarani, Valerio (2016). A new device-independent dimension witness and its experimental implementation. Journal of Physics A: Mathematical and Theoretical, 49 (30) 305301, 305301. doi: 10.1088/1751-8113/49/30/305301

  • Giovannini, Daniel, Romero, Jacquiline, Potocek, Vaclav, Ferenczi, Gergely, Speirits, Fiona, Barnett, Stephen M., Faccio, Daniele and Padgett, Miles J. (2015). Spatially structured photons that travel in free space slower than the speed of light. Science, 347 (6224), 857-860. doi: 10.1126/science.aaa3035

  • Romero, Jacquiline and Padgett, Miles (2014). Practical bound for dimensionality in high-dimensional entanglement. Proceedings of the National Academy of Sciences of the United States of America, 111 (17), 6122-6123. doi: 10.1073/pnas.1404903111

  • Chen, Lixiang, Lei, Jijin and Romero, Jacquiline (2014). Quantum digital spiral imaging. Light: Science and Applications, 3 (3) 201434, e153-e153. doi: 10.1038/lsa.2014.34

  • Giovannini, D., Romero, J. and Padgett, M. J. (2014). Interference of probability amplitudes: a simple demonstration within the Hong-Ou-Mandel experiment. Journal of Optics, 16 (3), 032002. doi: 10.1088/2040-8978/16/3/032002

  • McLaren, Melanie, Romero, Jacquiline, Padgett, Miles J., Roux, Filippus S. and Forbes, Andrew (2013). Two-photon optics of Bessel-Gaussian modes. Physical Review A, 88 (3). doi: 10.1103/PhysRevA.88.033818

  • Romero, J., Giovannini, D., Tasca, D. S., Barnett, S. M. and Padgett, M. J. (2013). Tailored two-photon correlation and fair-sampling: a cautionary tale. New Journal of Physics, 15 (8) 083047, 083047. doi: 10.1088/1367-2630/15/8/083047

  • Giovannini, D., Romero, J., Leach, J., Dudley, A., Forbes, A. and Padgett, M. J. (2013). Characterization of high-dimensional entangled systems via mutually unbiased measurements. Physical Review Letters, 110 (14) 143601. doi: 10.1103/PhysRevLett.110.143601

  • Chen, Lixiang and Romero, Jacquiline (2012). Hardy's nonlocality proof using twisted photons. Optics Express, 20 (19), 21687-21692. doi: 10.1364/OE.20.021687

  • Romero, J., Giovannini, D., McLaren, M. G., Galvez, E. J., Forbes, A. and Padgett, M. J. (2012). Orbital angular momentum correlations with a phase-flipped Gaussian mode pump beam. Journal of Optics, 14 (8), 085401. doi: 10.1088/2040-8978/14/8/085401

  • Romero, J., Giovannini, D., Franke-Arnold, S., Barnett, S. M. and Padgett, M. J. (2012). Increasing the dimension in high-dimensional two-photon orbital angular momentum entanglement. Physical Review A, 86 (1). doi: 10.1103/PhysRevA.86.012334

  • Miatto, F. M., Giovannini, D., Romero, J., Franke-Arnold, S., Barnett, S. M. and Padgett, M. J. (2012). Bounds and optimisation of orbital angular momentum bandwidths within parametric down-conversion systems. European Physical Journal D, 66 (7) 178. doi: 10.1140/epjd/e2012-20736-x

  • Giovannini, D., Miatto, F. M., Romero, J., Barnett, S. M., Woerdman, J. P. and Padgett, M. J. (2012). Determining the dimensionality of bipartite orbital-angular-momentum entanglement using multi-sector phase masks. New Journal of Physics, 14 (7), 073046. doi: 10.1088/1367-2630/14/7/073046

  • Romero, J., Leach, J., Jack, B., Dennis, M. R., Franke-Arnold, S., Barnett, S. M. and Padgett, M. J. (2011). Entangled optical vortex links. Physical Review Letters, 106 (10). doi: 10.1103/PhysRevLett.106.100407

  • Romero, J., Leach, J., Jack, B., Barnett, S. M., Padgett, M. J. and Franke-Arnold, S. (2010). Violation of Leggett inequalities in orbital angular momentum subspaces. New Journal of Physics, 12 (12), 123007. doi: 10.1088/1367-2630/12/12/123007

  • Leach, Jonathan, Jack, Barry, Romero, Jacqui, Jha, Anand K., Yao, Alison M., Franke-Arnold, Sonja, Ireland, David G., Boyd, Robert W., Barnett, Stephen M. and Padgett, Miles J. (2010). Quantum correlations in optical angle-orbital angular momentum variables. Science, 329 (5992), 662-665. doi: 10.1126/science.1190523

  • Jack, B., Yao, A. M., Leach, J., Romero, J., Franke-Arnold, S., Ireland, D. G., Barnett, S. M. and Padgett, M. J. (2010). Entanglement of arbitrary superpositions of modes within two-dimensional orbital angular momentum state spaces. Physical Review A: Atomic, Molecular, and Optical Physics, 81 (4), 043844-1-043844-5. doi: 10.1103/PhysRevA.81.043844

  • Romero, Mary Jacquiline, Bautista, Godofredo, Jr., Ricardo Daria, Vincent and Saloma, Caesar (2010). Laser confocal microscope with wavelet-profiled point spread function. Optics Communications, 283 (7), 1217-1221. doi: 10.1016/j.optcom.2009.11.077

  • Bautista, Godofredo, Romero, Mary Jacquiline, Tapang, Giovanni and Daria, Vincent Ricardo (2009). Parallel two-photon photopolymerization of microgear patterns. Optics Communications, 282 (18), 3746-3750. doi: 10.1016/j.optcom.2009.06.047

  • Jack, B., Leach, J., Romero, J., Franke-Arnold, S., Ritsch-Marte, M., Barnett, S. M. and Padgett, M. J. (2009). Holographic ghost imaging and the violation of a bell inequality. Physical Review Letters, 103 (8) 083602. doi: 10.1103/PhysRevLett.103.083602

  • Leach, J., Jack, B., Romero, J., Ritsch-Marte, M., Boyd, R. W., Jha, A. K., Barnett, S. M., Franke-Arnold, S. and Padgett, M. J. (2009). Violation of a bell inequality in two-dimensional orbital angular momentum state-spaces. Optics Express, 17 (10), 8287-8293. doi: 10.1364/OE.17.008287

  • Romero, Mary Jacquiline and Daria, Vincent Ricardo (2007). Modified filter design to optimize the synthetic reference wave in the generalized phase contrast method. Optics Communications, 280 (2), 237-242. doi: 10.1016/j.optcom.2007.08.029

Conference Publication

  • Rambach, Markus, Qaryan, Mahdi, Kewming, Michael, Ferrie, Christopher, White, Andrew G. and Romero, Jacquiline (2021). Robust and efficient high-dimensional quantum state tomography. Conference on Lasers and Electro-Optics Europe / European Quantum Electronics Conference (CLEO/Europe-EQEC), Munich, Germany, 21-25 June 2021. New York, NY, United States: Institute of Electrical and Electronics Engineers. doi: 10.1109/CLEO/Europe-EQEC52157.2021.9541925

  • Dahl, Daniel S., Romero, Jacquiline, Ploschner, Martin, Fontaine, Nicolas K. and Carpenter, Joel (2020). High-dimensional quantum gates for azimuthal modes. Conference on Lasers and Electro-Optics/Pacific Rim 2020, Sydney, Australia, 3–5 August 2020. Washington, DC, United States: OSA. doi: 10.1364/cleopr.2020.p5_2

  • Kewming, Michael J., Shrapnel, Sally, White, Andrew G. and Romero, Jacquiline (2019). Ignorance of the whole does not imply ignorance of the parts: qudit random access codes in spatial modes of light. Quantum Information and Measurement, QIM 2019, Rome, Italy, 4 - 6 April 2019. Washington, DC, United States: The Optical Society. doi: 10.1364/QIM.2019.F5A.78

  • Romero, Jacquiline, Goswami, Kaumudibikash, Giarmatzi, Christina, Costa, Fabio, Branciard, Cyril and White, Andrew G. (2018). Spatial modes for testing indefinite causal order. Complex Light and Optical Forces XII 2018, San Francisco, CA, United States, 30 January - 1 February 2018. Bellingham, WA, United States: SPIE. doi: 10.1117/12.2292732

  • Roger, Thomas, Restuccia, Sara, Lyons, Ashley, Giovannini, Daniel, Romero, Jacquiline, Jeffers, John, Padgett, Miles and Faccio, Daniele (2016). Coherent absorption of N00N states. 2016 Conference on Lasers and Electro-Optics (CLEO), San Jose, CA USA, 5-10 June 2016. Piscataway, NJ USA: Institute of Electrical and Electronics Engineers. doi: 10.1364/CLEO_QELS.2016.FM1D.6

Grants (Administered at UQ)

PhD and MPhil Supervision

Current Supervision

  • Doctor Philosophy — Principal Advisor

    Other advisors:

  • Doctor Philosophy — Principal Advisor

    Other advisors:

  • Doctor Philosophy — Principal Advisor

Completed Supervision