Second quantum revolution, or Why it’s time to study quantum physics A. Zagoskin Department of Physics Loughborough University Russian Quantum Centre Summer School 2016 August 25, 2016

DWave – international network + Harvard case study + 23 patents; books (Japan, China; Cambridge); outreach promoting science to school students http://journal.frontiersin.org/journal/ict/section/quantum-computing

I. Life and science

Due to its technology, the humanity is more powerful than ever… …and more than ever vulnerable if technology fails.

Great Ice Storm Canada, 1998

Getting rid of technology and going back to nature would require reducing the human population of this planet by 99.99%. Not an option!

We cannot survive and flourish without technology Technology cannot survive and develop without science. Therefore we must understand science, even though science nowadays is very advanced, complicated and counterintuitive.

We must understand science better than that! This is a vital and especially demanding task in the age of Second Quantum Revolution.

II. A brief story of Schrödinger’s cat

Quantum mechanics is arguably the most reliable scientific theory SO FAR IT MADE ZERO MISTAKES

Niels Bohr(1885 – 1962) Bohr’s postulates* (1913) Quantized orbits Quantum leaps

Louis de Broglie (1892 – 1987) Particle-wave duality* (1924)

Werner Heisenberg (1901 – 1976) Matrix mechanics (1925) (in the middle) Matrix mechanics (1925) +M. Born and P. Jordan Uncertainty principle

Erwin Schrödinger(1887 – 1961) Wave mechanics(1926) «Schrödinger’s cat»

Ra Ra Ra

Paul Dirac(1902 – 1984) Wave mechanics = matrix mechanics = quantum mechanics

Max Born(1882 – 1970) Matrix mechanics Probabilistic interpretation Entanglement - «spooky action at a distance»

Quantum mechanics showed that Nature is RANDOM & NONLOCAL

Physicists did not care, since it mattered for microscopic particles only

By necessity, all popular interpretations of quantum mechanics are wrong Some of them are significantly more wrong than the rest

First quantum revolution(1945-1970) Only microscopic quantum coherent systems: Quantum superpositions involved a small number of microscopic quantum states

First quantum revolution: outcomes Nuclear power Fission Fusion Semiconductor electronics Tunnelling Band theory Lasers Photon-atom interactions Quantum statistics Superconductors Cooper pairing Josephson effect

But by 1999 physicists got really interested in quantum computing.

Richard Feynman(1918 – 1988) Path integrals: an elegant link between quantum and classical mechanics Hero of Alexandria– Fermat – Lagrange – Hamilton - Dirac 1 2

A quantum system takes all paths at once! Therefore a big quantum system cannot be simulated with a classical computer. But it can be simulated with a quantum computer. What if a quantum computer can check all solutions at once? ю

Steam-powered Pentium™ is hard to make…

On s’engage et puis on voit

This means “let’s engage first and see what happens”. Of course, it did not work that well for Napoleon himself in Russia…

…which is necessary and useful, but should never ever be in the lead

III. Second quantum revolution

Superconducting qubits Phase qubit: Allman et al., 2010 Natural coming from q. computing side; 128 -> 512 – already a “medium” Charge qubits: Yamamoto et al., 2003 Flux qubits: Grajcar et al., 2006

Latest generation Chimaera C12 King et al. arxiv 1508.05087

Amazing evolution of superconducting qubits – like the development of aviation a hundred years ago 1999 – <10 ns 2015 – >100 µs Operating time - nanoseconds

…still a far cry to a universal quantum computer

Quantum slide rules: Analogue quantum devices 𝐻 𝜆 = 𝐻 𝑖 1−𝜆 + 𝐻 𝑓 𝜆

D-Wave: success and controversy...

IV. Not only quantum computers

Grand Challenge

Grand Challenge

What to expect? Quantum… Communications Solvers Sensors, detectors and image processors Simulators of complex physical, chemical, biological and social systems Pokemons?

Structural engineering Unit engineering Structural engineering Systems engineering

Humans only understand what they use… A major result of the second quantum revolution may be the public understanding of quantum mechanics: Humans only understand what they use… …and even that but rarely