New Paths into the World of Quasiparticles

Quasiparticles can be used to explain physical phenomena in solid bodies even though they are not actual physical particles. Physicists in Innsbruck have now realized quasiparticles in a quantum system and observed quantum mechanical entanglement propagation in a many-body system. Christian Roos' research team at the Institute for Quantum Optics and Quantum Information at the Austrian Academy of Sciences in Innsbruck has established a new experimental platform for investigating quantum phenomena: In a string of trapped ultracold ions they can precisely initialise, control and measure the states and properties of quasiparticle excitations in a many-body quantum system. "Quasiparticles are a well-established concept in physics to describe the collective behaviour of particles in a simplified way," says Christian Roos. Entanglement propagation. For the experiment the physicists used a one-dimensional ion-string consisting of between seven and fifteen calcium ions trapped in a vacuum chamber. Laser beams then manipulate the quantum state of the ions.