Dr Tom Siday MPhys, PhD, MInstP

School of Physics and Astronomy
Assistant Professor

Contact details

Email: t.siday@bham.ac.uk

Address: School of Physics and Astronomy
University of Birmingham
Edgbaston
Birmingham
B15 2TT
UK

Tom's research is based on developing microscopy techniques which can simultaneously access the very fast and the very small, to understand better how light interacts with matter.

He uses ultra-short light pulses to access extreme time resolution: around one ten-trillionth of a second, combined with bespoke microscopy techniques based on optical near fields. Tom combines these concepts to trace how dynamical processes within materials unfold in real time, with spatial resolution down to a single atom.

This combination of imaging in both time and space unveils a unique perspective on the fundamental properties and quantum dynamics of matter. Tom's group - the Birmingham Lightwave Collective - works within the wider Metamaterials and Nanophotonics research group.

Qualifications

Fulford Junior Research Fellow, Somerville College, Oxford
PhD in Electronic and Electrical Engineering, University College London
MPhs in Physics, University of York

Biography

Dr Tom Siday received a Master of Physics degree from the University of York (2015) and completed his PhD in Electronic & Electrical Engineering at University College London (2020). His PhD thesis (pdf) focused on boosting the sensitivity of near-field microscopes through the development of perfectly absorbing terahertz detectors and resonant antenna probes.

After his PhD, Tom spent 3 years (2019-2022) as a Postdoctoral Researcher at the University of Regensburg, Germany. After this he returned to the UK as a Postdoctoral Researcher at the University of Oxford (2023-2024). During this period, Tom was also awarded a Fulford Junior Research Fellowship at Somerville College. In these postdoctoral positions, he spent time developing new ways to access ultrafast dynamics on nanometre and atomic length scales and applied these techniques to a range of material systems: from two-dimensional semiconductors to light-harvesting materials.

Teaching

Physics Laboratory 2

Research

Over his career, Tom's research interests have spanned everything from probing fundamental quantum dynamics in materials to developing new and practical ways to measure terahertz (10¹² Hz) light.

Currently, his work primarily focuses on developing bespoke techniques for ultrafast microscopy, to probe how quantum processes in materials play out in real time and real space:

Nanoscale and atomic ultrafast probes

Using sharp metal tips, it is possible to confine short pulses of light down to a few tens of nanometres using evanescent near fields. Combined with techniques like atomic force microscopy, these confined fields form the core of a powerful ultrafast nanoscope.

To reach the atomic scale, we can exploit nonlinearities hidden deep within the near fields of a nanoscope, such as the quantum tunnelling of electrons. This gives direct access to the length scale of a few atoms with femtosecond time resolution.

Microscale spectroscopy

While atomic- and nanoscale probes provide very fundamental and direct answers about light-matter interaction, the emergent properties of quantum materials are often more apparent across slightly larger length scales (~1-100 µm) – especially when the energy scale of collective excitations is in the terahertz range. To access these length scales, a small aperture can be used instead of a tip to efficiently collect evanescent near fields.

Ultrafast dynamics in two-dimensional quantum materials

The elusive quantum states of matter hosted by two-dimensional van der Waals materials – especially when stacked and twisted to form moiré superlattices –provides an extensive platform for investigating unconventional quantum processes. Yet, measuring the dynamical processes which govern these peculiar properties in many cases can only be access with ultrafast microscopy techniques. Tip-based nanoscopes can directly access the intrinsic length scale of moiré superlattices (≲ 10 nm), and aperture microscopes provide probably the only route to directly sampling the dynamics of tiny (~10 µm) scale samples over ultrafast timescales.

Developing terahertz technologies

The sensitive measurement of electromagnetic fields is at the core of all microscopies. Hence, Tom has invested significant time into improving the sensitivity and efficiency of these methods. In particular, he developed a metasurface design which can perfectly absorb light. This allowed for a dramatic improvement in efficiency as well as shrinking detector dimensions down to the nanoscale. He has also developed new ways to resonantly enhance the efficiency of tip-based nanoscopes.

Image credit: Debs Allan of Debs Allan Photography (headshot), Brad Baxley, PtW (atomic scale probes)

Publications

Highlight publications

Siday, T, Hayes, J, Schiegl, F, Sandner, F, Menden, P, Bergbauer, V, Zizlsperger, M, Nerreter, S, Lingl, S, Repp, J, Wilhelm, J, Huber, MA, Gerasimenko, YA & Huber, R 2024, 'All-optical subcycle microscopy on atomic length scales', Nature, vol. 629, no. 8011, pp. 329-334. https://doi.org/10.1038/s41586-024-07355-7

Siday, T, Sandner, F, Brem, S, Zizlsperger, M, Perea-Causin, R, Schiegl, F, Nerreter, S, Plankl, M, Merkl, P, Mooshammer, F, Huber, MA, Malic, E & Huber, R 2022, Ultrafast Nanoscopy of an Exciton Mott Transition in Twisted Bilayer WSe₂. in 2022 47th International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz)., 9895814, International Conference on Infrared, Millimeter, and Terahertz Waves, IEEE, 47th International Conference on Infrared, Millimeter and Terahertz Waves, IRMMW-THz 2022, Delft, Netherlands, 28/08/22. https://doi.org/10.1109/IRMMW-THz50927.2022.9895814

Plankl, M, Faria Junior, PE, Mooshammer, F, Siday, T, Zizlsperger, M, Sandner, F, Schiegl, F, Maier, S, Huber, MA, Gmitra, M, Fabian, J, Boland, JL, Cocker, TL & Huber, R 2021, 'Subcycle contact-free nanoscopy of ultrafast interlayer transport in atomically thin heterostructures', Nature Photonics, vol. 15, no. 8, pp. 594-600. https://doi.org/10.1038/s41566-021-00813-y

Siday, T, Vabishchevich, PP, Hale, L, Harris, CT, Luk, TS, Reno, JL, Brener, I & Mitrofanov, O 2019, 'Terahertz Detection with Perfectly-Absorbing Photoconductive Metasurface', Nano Letters, vol. 19, no. 5, pp. 2888-2896. https://doi.org/10.1021/acs.nanolett.8b05118

Recent publications

Article

Lim, V-Y, Righetto, M, Farrar, MD, Siday, T, Snaith, HJ, Johnston, MB & Herz, LM 2025, 'Optically Determined Hole Effective Mass in Tin-Iodide Perovskite Films', ACS Energy Letters, vol. 10, no. 9, pp. 4589-4595. https://doi.org/10.1021/acsenergylett.5c02283

Wagner, FM, Haggren, T, Bürger, JC, Keat, TJ, Peng, K, Uswachoke, C, Damry, DA, Kraus, H, Joyce, HJ, Tan, HH, Jagadish, C, Siday, T & Johnston, MB 2025, 'The influence of subwavelength geometry on extracting the electrical properties of semiconductors by terahertz spectroscopy', APL Photonics, vol. 10, no. 7, 076123. https://doi.org/10.1063/5.0273919

Peng, K, Morgan, NP, Wagner, FM, Siday, T, Xia, CQ, Dede, D, Boureau, V, Piazza, V, Fontcuberta i Morral, A & Johnston, MB 2024, 'Direct and integrating sampling in terahertz receivers from wafer-scalable InAs nanowires', Nature Communications, vol. 15, no. 1, 103. https://doi.org/10.1038/s41467-023-44345-1

Zizlsperger, M, Nerreter, S, Yuan, Q, Lohmann, KB, Sandner, F, Schiegl, F, Meineke, C, Gerasimenko, YA, Herz, LM, Siday, T, Huber, MA, Johnston, MB & Huber, R 2024, 'In situ nanoscopy of single-grain nanomorphology and ultrafast carrier dynamics in metal halide perovskites', Nature Photonics, vol. 18, pp. 975–981. https://doi.org/10.1038/s41566-024-01476-1

Pistore, V, Schiattarella, C, Viti, L, Siday, T, Johnston, MB, Mitrofanov, O & Vitiello, MS 2024, 'Near-field probes for sensitive detectorless near-field nanoscopy in the 2.0-4.6 THz range', Applied Physics Letters, vol. 124, no. 22, 221105. https://doi.org/10.1063/5.0179714

Conference contribution

Schiegl, F, Siday, T, Hayes, J, Sandner, F, Menden, P, Bergbauer, V, Zizlsperger, M, Nerreter, S, Lingl, S, Repp, J, Wilhelm, J, Huber, MA, Gerasimenko, YA & Huber, R 2025, All-optical microscopy with combined atomic-scale spatial and subcycle temporal resolution. in 2025 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)., 11110169, Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference, IEEE, 2025 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2025, Munich, Germany, 23/06/25. https://doi.org/10.1109/CLEO/EUROPE-EQEC65582.2025.11110169

Schiegl, F, Siday, T, Hayes, J, Sandner, F, Menden, P, Bergbauer, V, Zizlsperger, M, Nerreter, S, Lingl, S, Repp, J, Wilhelm, J, Huber, MA, Gerasimenko, YA & Huber, R 2025, All-optical microscopy with combined subcycle temporal and atomic-scale spatial resolution. in LP Sadwick & T Yang (eds), Terahertz, RF, Millimeter, and Submillimeter-Wave Technology and Applications XVIII., 133650O, Proceedings of SPIE - The International Society for Optical Engineering, vol. 13365, SPIE, Terahertz, RF, Millimeter, and Submillimeter-Wave Technology and Applications XVIII 2025, San Francisco, United States, 27/01/25. https://doi.org/10.1117/12.3051117

Nerreter, S, Zizlsperger, M, Yuan, Q, Lohmann, KB, Sandner, F, Schiegl, F, Meineke, C, Gerasimenko, YA, Herz, LM, Siday, T, Huber, MA, Johnston, MB & Huber, R 2025, Ultrafast Nanoscopy of Carrier Dynamics and Nanoscale Morphology in Metal Halide Perovskites. in 2025 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)., 11109112, Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference, IEEE, 2025 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2025, Munich, Germany, 23/06/25. https://doi.org/10.1109/CLEO/EUROPE-EQEC65582.2025.11109112

Hayes, J, Siday, T, Schiegl, F, Sandner, F, Menden, P, Bergbauer, V, Zizlsperger, M, Nerreter, S, Lingl, S, Repp, J, Wilhelm, J, Huber, MA, Gerasimenko, YA & Huber, R 2024, All-Optical Subcycle Microscopy at the Atomic Scale. in CLEO: Fundamental Science 2024. CLEO: Fundamental Science, Optica Publishing Group (formerly OSA), 2024 Conference on Lasers and Electro-Optics, Charlotte, North Carolina, United States, 5/05/24. https://doi.org/10.1364/CLEO_FS.2024.FTh5B.6

Zizlsperger, M, Nerreter, S, Yuan, Q, Lohmann, KB, Sandner, F, Schiegl, F, Meineke, C, Gerasimenko, Y, Herz, LM, Siday, T, Huber, MA, Johnston, MB & Huber, R 2024, In-situ nanoscopy of carrier dynamics and nanomorphology in metal halide perovskites. in 2024 49th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)., 10697741, International Conference on Infrared, Millimeter, and Terahertz Waves , IEEE, 49th International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz 2024, Perth, Australia, 1/09/24. https://doi.org/10.1109/IRMMW-THz60956.2024.10697741

Peng, K, Morgan, N, Wagner, F, Siday, T, Xia, C, Dede, D, Boureau, V, Piazza, V, Fontcuberta I Morral, A & Johnston, M 2024, Scalable Receivers Based on Horizontally-grown InAs Nanowires Promise All-fiber Terahertz Spectrometer Systems. in 2024 49th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)., 10697914, International Conference on Infrared, Millimeter, and Terahertz Waves, IEEE, 49th International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz 2024, Perth, Australia, 1/09/24. https://doi.org/10.1109/IRMMW-THz60956.2024.10697914

Schiegl, F, Siday, T, Hayes, J, Menden, P, Bergbauer, V, Nerreter, S, Lingl, S, Wilhelm, J, Huber, MA, Gerasimenko, YA & Huber, R 2024, Subcycle optical microscopy with Angstrom-scale resolution. in M Razeghi & M Jarrahi (eds), Terahertz Emitters, Receivers, and Applications XV., 131410D, Proceedings of SPIE, the International Society for Optical Engineering, vol. 13141, SPIE, Terahertz Emitters, Receivers, and Applications XV 2024, San Diego, United States, 18/08/24. https://doi.org/10.1117/12.3029407

Letter

Schiegl, F, Bergbauer, V, Nerreter, S, Giessibl, V, Sandner, F, Giessibl, FJ, Gerasimenko, YA, Siday, T, Huber, MA & Huber, R 2026, 'Atomic-Scale Optical Microscopy with Continuous-Wave Mid-Infrared Radiation', Nano letters, vol. 26, no. 5, pp. 1689-1696. https://doi.org/10.1021/acs.nanolett.5c05319

Lim, VJY, Righetto, M, Yan, S, Patel, JB, Siday, T, Putland, B, McCall, KM, Sirtl, MT, Kominko, Y, Peng, J, Lin, Q, Bein, T, Kovalenko, M, Snaith, HJ, Johnston, MB & Herz, LM 2024, 'Contrasting Ultra-Low Frequency Raman and Infrared Modes in Emerging Metal Halides for Photovoltaics', ACS Energy Letters, vol. 9, no. 8, pp. 4127-4135. https://doi.org/10.1021/acsenergylett.4c01473

Norman, S, Chu, G, Peng, K, Seddon, J, Hale, LL, Tan, HH, Jagadish, C, Mouthaan, R, Alexander-Webber, J, Joyce, HJ, Johnston, MB, Mitrofanov, O & Siday, T 2024, 'Resonance-Amplified Terahertz Near-Field Spectroscopy of a Single Nanowire', Nano Letters, vol. 24, no. 49, pp. 15716-15723. https://doi.org/10.1021/acs.nanolett.4c04395

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