London, September 23 : An international team of British and American researchers has achieved a significant breakthrough in understanding the Kondo effect, an intriguing phenomenon in fundamental physics wherein many particles collectively behave as a single quantum-mechanical body.
The researchers - including experts from University College London (UCL) and the IBM Almaden Research Center - point out that when a single magnetic atom is located inside a metal, the free electrons of the metal 'screen' the atom, causing a cloud of many electrons around the atom to become magnetized.
If the metal is cooled down to very low temperatures, the atomic spin sometimes enters a so-called 'quantum superposition' state in which its north-pole points in two opposite directions at the same time, and the entire electron cloud around the spin gets magnetized in two directions.
The researchers say that a technique they had developed in 2007 can help predict when the Kondo effect will occur, and why.
The key turns out to be in the geometry of a magnetic atom's immediate surroundings, they add.
According to them, carefully studying how this geometry influences the magnetic moment or spin of the atom can help predict and understand the emergence of the Kondo effect.
"This result represents a major advance in our understanding of this fundamental physical phenomenon and could have important consequences for future nanoscale magnetic devices," Nature magazine quoted Dr. Cyrus Hirjibehedin, a member of the IBM team who is now a Lecturer at UCL, as saying.
The findings are reported online today in the scientific journal Nature Physics.