Using quantum states for storing and processing information has its pros and cons. If we manage to control a large number of the so called qubits that are used to process the data, we may be heading towards a new era of supercomputing. Small scale quantum computers may be able to outperform the fastest supercomputers of today, at a fraction of the cost. There have been many advances during the last year and the latest comes from a group of scientists that have discovered a hidden quantum order that stretches over up to 100 atoms. The hidden order shows that there is a magnetic property of a collection of atoms that otherwise seems unorganized and scattered.
Quantum mechanics is normally appreciated only on the atomic scale. However, here we present evidence for a very long and very quantum mechanical magnetic molecule,” Broholm said. “While disordered to a classical observer, the magnetic moments of almost 100 nickel atoms arranged in a row within a solid were shown to display an underlying quantum coherence limited only by chemical and thermal impurities. The progress we made is really a demonstration of quantum coherence among a larger number of atoms in a magnet than ever before. – Collin Broholm, professor in the Henry A. Rowland Department of Physics and Astronomy at Johns Hopkins’ Krieger School of Arts and Sciences
The scientists were also able to determine how long the hidden order stretches and what properties affects the order by introducing defects through heating and chemical impurities.
The study was made on chains of nickel atoms centered in octahedral oxygen laid end to end. The ceramic acts like tiny (quantum) bar magnets lacking any particular order. The scientists shot neutrons at the ceramic and discovered that even though there were not apparent magnetic order, magnetic excitation could propagate over relatively large distances. As much as 30nm at low temperatures.
The study was published in the latest issue of science (July 26).
