Quantum theory has opened to us the microscopic world of particles, atoms and photons..and has given us the keys of modern technologies

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Alisha Hill
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1 Power and strangeness of the quantum Quantum theory has opened to us the microscopic world of particles, atoms and photons.and has given us the keys of modern technologies This is a theory whose logics challenges our classical intuition, even if its strangeness remains generally veiled at the macroscopic level Recent experiments lead us to believe that the microscopic strangeness of quantum physics could be harnessed to realize new tools for communicating, computing or measuring things better

2 atoms Molecules and chemistry solids Quantum physics: a theory of everything cosmology

3 Lasers Computers

4 Progress in technology Moore s law: every 18 months computer power doubles ENIAC (1947) Pentium 4 (2002) from: Gordon E. Moore No exponential is forever 1 atom faster = smaller

5 Atomic clocks and GPS Geo-localization within 1 meter on surface of earth!

6 Quantum physics is based on the waveparticle duality and the superposition principle Light is a wave and an ensemble of photons (Einstein 1905) Atoms are particles and matter waves (de Broglie, 1923)

7 Quantum physics and the superposition principle x y Superposition of positions >= X> + Y> or superposition of atomic states of different energies +

8 The measurement: a random result Here or there? God is playing dice

9 Decoherence Environment or The environment «spies» on quantum systems and destroys their quantum coherence very efficiently

10 Thought experiments Einstein, Bohr and their Photon Box

11 How thoughts experiments controlling a «zoo of particles» have become real New quantum technologies: Tuneable Lasers Fast computers Supraconducting materials

12 «Particle control in a quantum world» The Boulder experiments (David Wineland)

13 «Particle control in a quantum world» The Paris experiments (SH)

We never experiments with single electrons, atoms or small molecules In thought experiments we assume that we do.

14 Why is it important to be able to manipulate single quantum particles? Curiosity: is it possible? How does Nature behaves at this level? We never experiments with single electrons, atoms or small molecules In thought experiments we assume that we do. It always results in ridiculous consequences» (Schrödinger 1952) Small systems reacts faster and pack more information per unit volume, leading to more powerful devices (Moore s law) Quantum physics makes a wide range of new states accessible for possible applications

15 More powerful computers and/or simulators (quantum logic) More secrete communications (quantum cryptography) More precise measurements (quantum metrology)

16 number of atoms per bit Progress in technology How many atoms per bit? ENIAC (1947) ~ Pentium 4 (2002) atom per bit Pentium 4 22 nm transistor year atom faster = smaller R. W. Keyes, IBM J. R&D 32, 26 (1988)

17 A computer in a Schrödinger cat state to break the RSA code? Quantum computers would exploit state superpositions and entanglement in ensemble of real or artificial atoms to compute more efficiently Decoherence is the big challenge. Ways to correct for it are investigated. Proof of principle experiments under way with small ensembles of atoms

18 Quantum simulators Atoms in optical lattices to simulate solid state structures

Another illustration of the law smaller is faster and better : Clock speed and

1,E+09 10 9 1,E+12 10 12 1,E+15 10 15 1,E+00 1 1,E-01 Frequency [Hz] 1,E-02

10-12 1,E-12 1,E-13 1,E-14 10-15 1,E-15 1,E-16 1,E-17 10-18 1,E-18 Sundial

Period 1 s Accuracy 10 ms Quartz Period 100 ns Accuracy 10-10 Cesium fountain

19 Another illustration of the law smaller is faster and better : Clock speed and accuracy vs time 1,E ,E ,E ,E ,E ,E ,E ,E ,E ,E-01 Frequency [Hz] 1,E-02 1,E ,E-04 1,E ,E-06 1,E-07 1,E ,E-09 1,E-10 1,E ,E-12 1,E-13 1,E ,E-15 1,E-16 1,E ,E-18 Sundial Period = 1 day Accuracy 1-10 minutes Fractional accuracy at one day Pendulum Period 1 s Accuracy 10 ms Quartz Period 100 ns Accuracy Cesium fountain Period 108 ps Accuracy 3x10-16 Towards accuracy? Al+ optical Period 1 fs Accuracy 8.6x10-18

20 27 Al + vs. 27 Al + C.-W. Chou, et al. PRL 104, (2010) Comparing two single ion clocks (David Wineland group at NIST)

33 General relativity test: clocks 33 cm apart in gravitational fields tick at different rates! 33 cm Measured: Expected: (37 +/- 15 cm) (33 cm) C. W. Chou, et al. Science 329, 1630 (2010)

34 Practical applications for clocks keeping time within a handful of seconds in the age of the Universe? Better GPS able to track very small motions (at millimeter scale?) Geodesic surveys (oil prospection?) Earthquakes warnings?

35 Unpredictability of blue sky research Laser (1960) Highly transparent optical fibers (1970 s) Transistors and Integrated circuits ( s) Global communication network Towards a quantum internet?

36 Magnetic resonance imaging (MRI) + + Superconducting magnets (1970 s) Magnetic resonance (1946) Fast small Computers (1970 s)

37 It is hard to make predictions, especially about the future (Attributed to Niels Bohr) but one thing is sure: without basic research, novel technologies cannot be invented and the past teaches us that wonderful applications always emerge serendipitously from blue sky research

Future of Quantum Science and Technology

Future of Quantum Science and Technology Serge Haroche S.H &D.Wineland, 2012 Nobel in Physics Quantum theory has opened to us the microscopic world of particles, atoms and photons.and has given us the