Conférence IPR 30/01/18 : Serge HAROCHE "Puissance et étrangeté de la physique quantique"

Institut de Physique de Rennes

Institut de Physique de Rennes

45,484 views

Serge Haroche, 2012 Nobel Prize in Physics, discusses the power and strangeness of quantum physics.

Summary: Born nearly a century ago, quantum physics has provided us with the essential concepts for understanding the microscopic world of elementary particles, atoms, and photons. Its applications (electronics, computers, lasers, magnetic resonance imaging, atomic clocks, etc.) have revolutionized our daily lives. And yet, despite all its successes, this physics appears strange to our intuition, shaped by the observation of the macroscopic world. This strangeness is illustrated by the famous metaphor of the cat that the Austrian physicist Schrödinger imagined suspended by quantum laws between life and death. The fundamental quantum principles—the superposition of states, which implies that a particle can behave like a wave, and entanglement, which leads to a strange non-locality in the laws of nature—are, however, only directly observable at the scale of atoms and particles. At the macroscopic level, which is familiar to us, these bizarre manifestations are obscured by the phenomenon of decoherence, which gives the world a familiar classical appearance. In recent years, however, technological advances have made it possible to directly manipulate isolated quantum systems (atoms, molecules, photons, superconducting microcircuits, etc.). These experiments have paved the way for the direct observation of counterintuitive aspects of quantum behavior. Beyond their fundamental interest, they offer a glimpse of new technologies in which quantum strangeness could be directly harnessed. These include cryptography, metrology, simulators, and quantum computers. Whether or not these applications come to fruition, the in-depth exploration of the strange laws of the quantum world promises us further surprises and many reasons for wonder.