An international team of scientists studying ultrafast physics have solved a mystery of quantum mechanics, and found that quantum tunneling is an instantaneous process
The new theory could lead to faster and smaller electronic components, for which quantum tunneling is a significant factor. It will also lead to a better understanding of diverse areas such as electron microscopy, nuclear fusion and DNA mutations.
"Timescales this short have never been explored before. It's an entirely new world," said one of the international team, Professor Anatoli Kheifets, from The Australian National University (ANU).
"We have modelled the most delicate processes of nature very accurately."
At very small scales quantum physics shows that particles such as electrons have wave-like properties - their exact position is not well defined. This means they can occasionally sneak through apparently impenetrable barriers, a phenomenon called quantum tunneling.
Quantum tunneling plays a role in a number of phenomena, such as nuclear fusion in the sun, scanning tunneling microscopy, and flash memory for computers. However, the leakage of particles also limits the miniaturisation of electronic components.
Professor Kheifets and Dr. Igor Ivanov, from the ANU Research School of Physics and Engineering, are members of a team which studied ultrafast experiments at the attosecond scale (10-18 seconds), a field that has developed in the last 15 years.
Until their work, a number of attosecond phenomena could not be adequately explained, such as the time delay when a photon ionised an atom.
"At that timescale the time an electron takes to quantum tunnel out of an atom was thought to be significant. But the mathematics says the time during tunneling is imaginary - a complex number - which we realised meant it must be an instantaneous process," said Professor Kheifets.
"A very interesting paradox arises, because electron velocity during tunneling may become greater than the speed of light. However, this does not contradict the special theory of relativity, as the tunneling velocity is also imaginary" said Dr Ivanov, who recently took up a position at the Center for Relativistic Laser Science in Korea.
The team's calculations, which were made using the Raijin supercomputer, revealed that the delay in photoionisation originates not from quantum tunneling but from the electric field of the nucleus attracting the escaping electron.
The results give an accurate calibration for future attosecond-scale research, said Professor Kheifets.
"It's a good reference point for future experiments, such as studying proteins unfolding, or speeding up electrons in microchips," he said.
Anatoli Kheifets | EurekAlert!
A tale of two pulsars' tails: Plumes offer geometry lessons to astronomers
18.01.2017 | Penn State
Studying fundamental particles in materials
17.01.2017 | Max-Planck-Institut für Struktur und Dynamik der Materie
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
18.01.2017 | Power and Electrical Engineering
18.01.2017 | Materials Sciences
18.01.2017 | Life Sciences