Items tagged with "atomic physics"
There’s a big unsolved mystery in physics: The cosmic balance sheet for matter in our universe just doesn’t add up. Galaxies all over space move as though they are much heavier than they appear. Scientists postulate that they are full of stuff we cannot see, stuff that they call dark matter.
Scientists at the Joint Quantum Institute (JQI) have observed, for the first time, interference between particles of light created using a trapped ion and a collection of neutral atoms. Their results could be an essential step toward the realization of a distributed network of quantum computers capable of processing information in novel ways.
Electrons inside an atom whip around the nucleus like satellites around the Earth, occupying orbits determined by quantum physics. Light can boost an electron to a different, more energetic orbit, but that high doesn’t last forever. At some point the excited electron will relax back to its original orbit, causing the atom to spontaneously emit light that scientists call fluorescence.
Large-scale quantum computers, which are an active pursuit of many university labs and tech giants, remain years away. But that hasn’t stopped some scientists from thinking ahead, to a time when quantum computers might be linked together in a network or a single quantum computer might be split up across many interconnected nodes.
The behavior of a few rubidium atoms in a cloud of 40,000 hardly seems important. But a handful of the tiny particles with the wrong energy may cause a cascade of effects that could impact future quantum computers.
Some proposals for quantum devices use Rydberg atoms—atoms with highly excited electrons that roam far from the nucleus—because they interact strongly with each other and offer easy handles for controlling their individual and collective behavior. Rubidium is one of the most popular elements for experimenting with Rydberg physics.
Phil Schewe discusses quantized energy levels with Steve Rolston (JQI) and Wes Campbell (former JQI postdoc and current UCLA professor). The concept of electronic energy levels in an atom has applications everywhere, from sodium lamps to brake lights to quantum information and atomic clocks.