Browse/search for people
# Dr Anthony Laing

## Dr Anthony Laing

MSc(Bristol), PhD(Bristol)

Senior Lecturer
## Summary

## Memberships

### Organisations

### Physics staff

### Research areas

### Research groups

## Selected publications

- All details
- Overview
- About
- Research
- Publications

MSc(Bristol), PhD(Bristol)

Office NSQI

HH Wills Physics Laboratory,

Tyndall Avenue,
Bristol
BS8 1TL

(See a map)

+44 (0) 117 3940020

anthony.laing@

bristol.ac.uk

**Quantum Technologies**

My group researches how new technologies can be realised by harnessing the unusual properties of quantum physics. Over the coming years and decades, this field is likely to have a profound impact upon society, bringing a technological revolution potentially as far reaching as that of the information age of the twentieth century, or the industrial revolution. Large state investments include £270M by the UK in 2014, and €1billion from Europe in 2018. Among the advances targeted by these investments are quantum computers and quantum simulators, which are believed capable of efficiently solving certain problems that would take conventional computers the lifetime of the universe to solve.

**Quantum Simulations using Photonic Chips**

Together with my students, postdocs and collaborators, I am focused on understanding how quantum technologies can be used to simulate microscopic physical systems. Large objects such as bridges or aeroplanes are heavily simulated on computers prior to their construction. However, microscopic systems that behave according to quantum mechanics, such as the dynamics of molecules or the interactions of atomic particles, are too complicated for conventional computers to efficiently simulate. This poses a problem, for example, to industrial chemists trying to design new catalysts, or to particle physicists trying to answer questions about the standard model. However, these and other problems could be investigated with a quantum simulator: a device that itself is quantum mechanical, but also highly controllable, and can be programmed to mimic the behaviour of other quantum systems.

**Simulating Molecular Quantum Dynamics**

We are developing new methods to simulate the quantum dynamics of molecules using single photons of light that are controlled by programmable optical chips. For example, data collected during a quantum simulation experiment can be fed into a machine learning algorithm, which iteratively searches for a control field that dissociates a molecule, such as ammonia, via a particular pathway. Other experiments have simulated energy transport processes for a molecular prototype of the peptide bond in proteins, and thermalisation of water molecules. We are also investigating methods for simulating particle physics, open system dynamics, and non-Hermitian Hamiltonians.

**The Limits of Conventional Computers for Quantum Simulation**

In parallel with these efforts, we are investigating the limits of classical computers to perform these simulations. This helps us to understand the types and sizes of problems for which quantum simulators might provide the first practical advantages over conventional methods. Pressing such a quantum advantage and furthering any separation between the capabilities of quantum and conventional simulators will likely require new error correction techniques. Developing error correction for our types of quantum simulator is another important direction for us.

**Quantum Technologies in Industry and in the UK**

Dr Laing is also known for inventing the Reference Frame Independent Quantum Key Distribution protocol, and patenting its implementation with Nokia. He is an investigator on the UK Quantum Communications Hub. He holds a 5 year EPSRC fellowship in quantum technologies.

- Sparrow, C, Lopez, EM, Maraviglia, N, Neville, A, Harrold, C, Carolan, J, Joglekar, Y, Hashimoto, T, Matsuda, N, O'Brien, J, Tew, D & Laing, A, 2018, ‘Simulating the vibrational quantum dynamics of molecules using photonics’.
*Nature*, vol 557., pp. 660-667 - Wang, J, Paesani, S, Ding, Y, Santagati, R, Skrzypczyk, P, Salavrakos, A, Tura, J, Augusiak, R, Mančinska, L, Bacco, D, Bonneau, D, Silverstone, JW, Gong, Q, Acín, A, Rottwitt, K, Oxenløwe, LK, O'Brien, JL, Laing, A & Thompson, MG, 2018, ‘Multidimensional quantum entanglement with large-scale integrated optics’.
*Science*, vol 360., pp. 285-291 - Neville, A, Sparrow, C, Clifford, R, Johnston, E, Birchall, P, Montanaro, A & Laing, A, 2017, ‘Classical boson sampling algorithms with superior performance to near-term experiments’.
*Nature Physics*, vol 13., pp. 1153-1157 - Wang, J, Paesani, S, Santagati, R, Knauer, S, Gentile, AA, Wiebe, N, Petruzzella, M, O’Brien, JL, Rarity, JG, Laing, A & Thompson, MG, 2017, ‘Experimental quantum Hamiltonian learning’.
*Nature Physics*, vol 13., pp. 551-555 - Carolan, J, Harrold, C, Sparrow, C, Lopez, EM, Russell, N, Silverstone, J, Shadbolt, P, Matsuda, N, Ogama, M, Itoh, M, Marshall, G, Thompson, M, Matthews, J, Hashimoto, T, O'Brien, J & Laing, A, 2015, ‘Universal linear optics’.
*Science*, vol 349., pp. 711-716 - Carolan, J, Meinecke, JDA, Shadbolt, PJS, Russell, NJ, Ismail, N, Wörhoff, K, Rudolph, T, Thompson, MG, O'Brien, JL, Matthews, JCF & Laing, A, 2014, ‘On the experimental verification of quantum complexity in linear optics’.
*Nature Photonics*, vol 8., pp. 621-626 - Lund, AP, Laing, A, Rahimi-Keshari, S, Rudolph, T, O'Brien, JL & Ralph, TC, 2014, ‘Boson Sampling from a Gaussian State’.
*Physical Review Letters*, vol 113. - Russell, NJ, Chakhmakhchyan, L, O'Brien, JL & Laing, A, 2017, ‘Direct dialling of Haar random unitary matrices’.
*New Journal of Physics*, vol 19. - Laing, A, 2012, ‘Telecom rfiQKD US20120195430’.
- Laing, A, Scarani, V, Rarity, J & O'Brien, J, 2010, ‘Reference-frame-independent quantum key distribution’.
*Physical Review A: Atomic, Molecular and Optical Physics*, vol 82 (1)., pp. 012304-1 - 012304-5 - Zhang, P, Aungskunsiri, K, Martín-López, E, Wabnig, J, Lobino, M, Nock, RW, Munns, J, Bonneau, D, Jiang, P, Li, HW, Laing, A, Rarity, JG, Niskanen, AO, Thompson, MG & O'Brien, JL, 2014, ‘Reference-frame-independent quantum-key-distribution server with a telecom tether for an on-chip client’.
*Physical Review Letters*, vol 112. - Wabnig, J, Bitauld, D, Li, HW, Laing, A, O'Brien, JL & Niskanen, AO, 2013, ‘Demonstration of free-space reference frame independent quantum key distribution’.
*New Journal of Physics*, vol 15. - Martin-Lopez, E, Laing, A, Lawson, TM, Alvarez, R, Zhou, X-Q & O'Brien, JL, 2012, ‘Experimental realization of Shor’s quantum factoring algorithm using qubit recycling’.
*Nature Photonics*, vol 6., pp. 773-776 - Shadbolt, PJ, Verde, MR, Peruzzo, A, Politi, A, Laing, A, Lobino, M, Matthews, JCF, Thompson, MG & O'Brien, JL, 2012, ‘Generating, manipulating and measuring entanglement and mixture with a reconfigurable photonic circuit’.
*Nature Photonics*, vol 6., pp. 45-49 - Peruzzo, A, Laing, A, Politi, A, Rudolph, T & O'Brien, J, 2011, ‘Multimode quantum interference of photons in multiport integrated devices’.
*Nature Communications*, vol 2. - Laing, A, Peruzzo, A, Politi, A, Verde, MR, Halder, M, Ralph, T, Thompson, M & O'Brien, J, 2010, ‘High-fidelity operation of quantum photonic circuits’.
*Applied Physics Letters*, vol 97 (21)., pp. 211109-1 - 211109-3 - H.W., L, S., P, A.O., N, Matthews, J, Politi, A, Shadbolt, PJS, Laing, A, Lobino, M, Thompson, M & O'Brien, J, 2011, ‘Reconfigurable controlled two-qubit operation on a quantum photonic chip’.
*New Journal of Physics*, vol 13 115009. - Laing, A, Lawson, T, Lopez, EM & O'Brien, JL, 2012, ‘Observation of Quantum Interference as a Function of Berry's Phase in a Complex Hadamard Optical Network’.
*Physical Review Letters*, vol 108., pp. - - Li, HW, Wabnig, J, Bitauld, D, Shadbolt, P, Politi, A, Laing, A, O'Brien, JL & Niskanen, AO, 2013, ‘Calibration and high fidelity measurement of a quantum photonic chip’.
*New Journal of Physics*, vol 15. - Laing, A, 2012, ‘Quantum Interference as a function of Berry's phase’. in:
*QCMC2012*.

View complete publications list in the University of Bristol publications system

Edit this profile If you are Dr Anthony Laing, you can edit this page. Login required.