Imperial College London


Faculty of Natural SciencesDepartment of Physics

Advanced Research Fellow







Blackett LaboratorySouth Kensington Campus





Dr Hobson's research is focused on developing cold-atom quantum technologies with exceptional precision, and using these technologies to explore fundamental questions of physics. As part of the Atom Interferometer Observatory and Network (AION), he is developing squeezed atom interferometers with the long-term goal to discover new signals from dark matter or gravitational waves. Separately, he has established a research theme on Ultra-precise Shock-resistant Optical Clocks (USOC), for which he is exploring new laser cooling methods to create a continuous stream of ultracold strontium atoms. By feeding the continuous stream of atoms into an atomic clock or atom interferometer, he hopes to reach unprecedented levels of stability and robustness with these quantum sensors.

Dr Hobson has been making state-of-the-art quantum sensors for more than ten years. During his PhD he established the first neutral-strontium atomic clock at the National Physical Laboratory (NPL) and invented new techniques to improve its accuracy. Coordinating measurements against other atomic clock labs across Europe, he used the clock to place new constraints on physics beyond the standard model. Later, he pioneered cavity-based quantum non-destructive detection of strontium, a crucial step toward ultra-precise, squeezed quantum sensors. He also created the world’s first metastable magneto-optical trap of strontium, a fundamental concept for his current work on USOC.

In 2019 he became a member of the core team of AION, an Imperial-led initiative with the goal of using strontium atom interferometers to search for dark matter and gravitational waves. As part of AION, he set up a cold-atom laboratory with Charles Baynham, taking on the task of creating squeezed states of strontium to reduce the detector shot noise, and ultimately the AION detector resolution, by a factor of 100. If these sensitivity targets can be achieved, it will pave the way to an atom-interferometer detector capable of exploring the wide gap between two of the most groundbreaking physics experiments of the last decade – NanoGrav and LIGO – which have so far only revealed gravitational waves which are either very slow (years) or very fast (milliseconds). By seeing waves with a period of a few seconds, he hopes to provide unique insights into how galaxies formed, and could observe primordial echoes from the big bang, potentially seeing the fingerprint of high-energy physics beyond the reach of even the largest particle colliders.

Selected Publications

Journal Articles

Bowden W, Vianello A, Hill IR, et al., 2020, Improving the <i>Q</i> Factor of an Optical Atomic Clock Using Quantum Nondemolition Measurement, Physical Review X, Vol:10, ISSN:2160-3308

Hobson R, Bowden W, Vianello A, et al., 2020, A strontium optical lattice clock with 1 x 10<SUP>-17</SUP> uncertainty and measurement of its absolute frequency, Metrologia, Vol:57, ISSN:0026-1394

Roberts BM, Delva P, Al-Masoudi A, et al., 2020, Search for transient variations of the fine structure constant and dark matter using fiber-linked optical atomic clocks, New Journal of Physics, Vol:22, ISSN:1367-2630

Badurina L, Bentine E, Blas D, et al., 2020, AION: an atom interferometer observatory and network, Journal of Cosmology and Astroparticle Physics, ISSN:1475-7516

El-Neaj YA, Alpigiani C, Amairi-Pyka S, et al., 2020, AEDGE: Atomic Experiment for Dark Matter and Gravity Exploration in Space, Epj Quantum Technology, Vol:7, ISSN:2662-4400

Hobson R, Bowden W, Vianello A, et al., 2019, Cavity-enhanced non-destructive detection of atoms for an optical lattice clock, Optics Express, Vol:27, ISSN:1094-4087, Pages:37099-37110

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