The Department of Physics and Astronomy proudly presents a colloquium featuring Dr. Mark Kasevich, Department of Physics, Stanford University. Dr. Kasevich will present his talk, “Quantum mechanics at the macroscopic scale”, Tuesday, Oct. 27 at 4:10 p.m. in Webster B17.
Meet for refreshments before the lecture at 3:45 – 4:10 p.m. in the foyer on floor G above the lecture hall.
Abstract: Imagine yourself racing down a ski slope and a collision with a 54 cm wide tree is imminent. You should make a sharp turn left or right to avoid a catastrophe. However, in the quantum world you can turn both left and right at the same time to continue your journey. Although counter to intuition, we manipulate an atom so that it simultaneously travels along two paths separated by more than half a meter, which is enough, in principle, to wrap around this tree. With our well-controlled system we demonstrate that the quantum world extends to this extreme scale. Quantum mechanics is a foundation of physics, chemistry and materials science. Still, there is an ongoing debate about the emergence of the classical, macroscopic world from the well-understood microscopic world of quantum mechanics. We contribute to this discourse by demonstrating quantum superposition of massive particles at the distance and time scales of everyday life, thereby advancing the state-of-the-art of atom interferometry by nearly two orders of magnitude. In addition to testing a central tenet of quantum mechanics, we pave the way for new precision tests of gravity, including the possible observation of gravitational waves and tests of the equivalence principle.
