physics

Jeremy O'Brien

Jeremy O'Brien is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Jeremy O'Brien rather than just read about it. In short: Jeremy O'Brien (born 1975, Australia) is a physicist who researches in quantum optics, optical quantum metrology and quantum information science. He co-founded and is CEO of the quantum computing firm PsiQuantum.

Key takeaways

Jeremy O'Brien belongs to physics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Jeremy O'Brien to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Jeremy O'Brien from memory before moving on to harder problems.

Reference excerpt

Jeremy O'Brien (born 1975, Australia) is a physicist who researches in quantum optics, optical quantum metrology and quantum information science. He co-founded and is CEO of the quantum computing firm PsiQuantum. Formerly, he was Professorial Research Fellow in Physics and Electrical Engineering at the University of Bristol, and director of its Centre for Quantum Photonics. His work in optical quantum computing has included the demonstration of the first optical quantum controlled NOT gate.

Honours and awards 2009 European Quantum Information Young Investigator Award 2010 Adolph Lomb Medal of the Optical Society of America 2010 IUPAP Prize in Atomic Molecular and Optical Physics 2010 Moseley medal and prize of the Institute of Physics 2010 Daiwa Adrian Prize 2011 Elected to the Global Young Academy "PsiQuantum Valuation". Retrieved 25 September 2025.

Selected publications O'Brien, JL; Schofield, S. R.; Simmons, M. Y.; Clark, R. G.; Dzurak, A. S.; Curson, N. J.; Kane, B. E.; McAlpine, N. S.; Hawley, M. E.; Brown, G. W. (2001). "Towards the fabrication of phosphorus qubits for a silicon quantum computer". Physical Review B. 64 (16) 161401. arXiv:cond-mat/0104569. Bibcode:2001PhRvB..64p1401O. doi:10.1103/PhysRevB.64.161401. S2CID 119494991. O'Brien, JL; Pryde, GJ; White, AG; Ralph, TC; Branning, D (2003). "Demonstration of an all-optical quantum controlled-NOT gate". Nature. 426 (6964): 264–267. arXiv:quant-ph/0403062. Bibcode:2003Natur.426..264O. doi:10.1038/nature02054. PMID 14628045. S2CID 9883628. O'Brien, Jeremy L. (2007). "Optical Quantum Computing". Science. 318 (5856): 1567–1570. arXiv:0803.1554. Bibcode:2007Sci...318.1567O. doi:10.1126/science.1142892. PMID 18063781. S2CID 15701944. Politi, Alberto; Cryan, Martin J.; Rarity, John G.; Yu, Siyuan; O'Brien, Jeremy L. (2008). "Silica-on-Silicon Waveguide Quantum Circuits". Science. 320 (5876): 646–9. arXiv:0802.0136. Bibcode:2008Sci...320..646P. doi:10.1126/science.1155441. PMID 18369104. S2CID 3234732. O'Brien, Jeremy L. (2008). "Quantum computing over the rainbow". Physics. 1 (23): 23. Bibcode:2008PhyOJ...1...23O. doi:10.1103/Physics.1.23.

References

External links Jeremy O'Brien: Home page. Department of Physics, University of Bristol. Professor Jeremy O'Brien. Department of Electrical & Electronic Engineering, University of Bristol. Jeremy O'Brien: Recent publications. Quantum Computation & Information Group, University of Bristol. PsiQuantum Valuation The Quantum Computing Pioneer

Illustrations

Worked examples

Example 1 — a first encounter with Jeremy O'Brien

Start with the simplest possible case. Write down what Jeremy O'Brien claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Jeremy O'Brien before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Jeremy O'Brien ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Jeremy O'Brien

In research: Jeremy O'Brien appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Jeremy O'Brien in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Jeremy O'Brien is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1975 births, Australian physicists, Fellows of the American Physical Society, so understanding it makes those chapters shorter.
In everyday life: Look for Jeremy O'Brien outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Jeremy O'Brien in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Jeremy O'Brien means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Jeremy O'Brien out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Jeremy O'Brien in simple terms?

Why does Jeremy O'Brien matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Jeremy O'Brien?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Jeremy O'Brien.