1. Catching photons for the future of computing
Josh Nunn
Centre for Photonics and Photonic Materials

2. Processing information

3. Computing

4. Bits made of atoms

5. Quantum bits
bit
qubit
Two points
A whole continuum of states…

6. Applications…
1994: Efficient factoring breaks public-key cryptography

7. Applications…
Search
Linear systems
Simulation
Machine learning

8. Which platform?

9. Which platform?

10. Which platform?

11. Which platform?

12. Which platform? Trapped ions… K donors in silicon…
Superconducting circuits…
Colour centres in diamond…

13. Some big players…
Needs to be very cold!

14. Integrated photonics Southampton, Oxford, Bristol… UK is leading…
Room temperature!

15. Logic gates? Photons don’t interact with each other!
Logic via interference + measurement

16. Logic gates? Why can’t I buy an optical quantum computer yet?
Probabilistic measurements = scaling catastrophe!
1 in 10
1 in 1000…
1 in 100

17. Multiplexing needed Why can’t I buy an optical quantum computer yet?
Probabilistic measurements = scaling catastrophe!
1 in 10
1 in 1000…
1 in 100
Synchronisation needed

18. Our solution:
Atomic ensemble
Raman absorption is reversible!

19. Towards a compact device…
Fibre technology from Bath!

20. Next steps at the CPPM…
Carlo Page
John Price
Pete Mosley

21. Support