Items tagged with "ion trap"
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.
Optical systems, like your eye, sometimes need help to produce a crystal clear image. And it’s not just a problem for eyes. Research labs, too, worry about aberrations and distortions that lead to image inaccuracies. JQI physicists have implemented a novel imaging technique that adapts to these destructive errors and corrects them. They combine high performance lenses, akin to an artificial eye, with computer processing to capture an image of a single atomic ion and its motion with unprecedented nanoscale sensitivity. The research is featured on the cover of the September issue of Nature Photonics.
High-resolution adaptive imaging of a single atom J. D. Wong-Campos, K. G. Johnson, B. Neyenhuis, J. Mizrahi & C. Monroe, Nature Photonics doi:10.1038/nphoton.2016.136
Nature doesn’t have the best memory. If you fill a box with air and divide it in half with a barrier, it’s easy to tell molecules on the left from molecules on the right. But after removing the barrier and waiting a short while, the molecules get mixed together, and it becomes impossible to tell where a given molecule started. The air-in-a-box system loses any memory of its initial conditions.
Harnessing quantum systems for information processing will require controlling large numbers of basic building blocks called qubits. The qubits must be isolated, and in most cases cooled such that, among other things, errors in qubit operations do not overwhelm the system, rendering it useless. Led by JQI Fellow Christopher Monroe, physicists have recently demonstrated important steps towards implementing a proposed type of gate, which does not rely on super-cooling their ion qubits.
A team of researchers led by Duke University and the University of Maryland has been tapped by the nation’s “Q Branch” to take quantum computing efforts to the next level using one of the field’s leading technologies—ion traps.
Symmetry permeates nature, from the radial symmetry of flowers to the left-right symmetry of the human body. As such, it provides a natural way of classifying objects by grouping those that share the same symmetry. This is particularly useful for describing transitions between phases of matter. For example, liquid and gas phases have translational symmetry, meaning the arrangement of molecules doesn’t change regardless of the direction from which they are observed.
JQI researchers, under the direction of Christopher Monroe have demonstrated modular entanglement between two atomic systems, separated by one meter. Here, photons are the long distance information carriers entangling multiple qubit modules.
Recently physicists led JQI Fellow Christopher Monroe have executed an MRI-like diagnostic on a crystal of interacting quantum spins. They predict that their method is scalable and may be useful for validating experiments with much larger ensembles of interacting spins.
Ions are charged particles that interact strongly via the Coulomb force, which is an attraction/repulsion that decreases as particles separate. When a handful of positively charged ions are thrown together, they repel each other, and, for an oblong ion trap, form a linear crystal. (Images of ion traps can be found in media galleries.) Each ion has two internal energy states that make up a qubit. Laser beams can manipulate the Coulomb force to create tunable, long range magnetic-like interactions, where each ion qubit represents a tiny magnet.
In quantum mechanics, interactions between particles can give rise to entanglement, which is a strange type of connection that could never be described by a non-quantum, classical theory. These connections, called quantum correlations, are present in entangled systems even if the objects are not physically linked (with wires, for example). Entanglement is at the heart of what distinguishes purely quantum systems from classical ones; it is why they are potentially useful, but it sometimes makes them very difficult to understand.