How can quantum information be transferred from one atom to another? A team of researchers from TU Wien and Harvard University has proposed using phonons -- the quanta of sound
Quantum physics is on the brink of a technological breakthrough: new types of sensors, secure data transmission methods and maybe even computers could be made possible thanks to quantum technologies. However, the main obstacle here is finding the right way to couple and precisely control a sufficient number of quantum systems (for example, individual atoms).
A team of researchers from TU Wien and Harvard University has found a new way to transfer the necessary quantum information. They propose using tiny mechanical vibrations. The atoms are coupled with each other by 'phonons' - the smallest quantum mechanical units of vibrations or sound waves.
Tiny diamonds with deliberate defects
"We are testing tiny diamonds with built-in silicon atoms - these quantum systems are particularly promising," says Professor Peter Rabl from TU Wien. "Normally, diamonds are made exclusively of carbon, but adding silicon atoms in certain places creates defects in the crystal lattice where quantum information can be stored." These microscopic flaws in the crystal lattice can be used like a tiny switch that can be switched between a state of higher energy and a state of lower energy using microwaves.
Together with a team from Harvard University, Peter Rabl's research group has developed a new idea to achieve the targeted coupling of these quantum memories within the diamond. One by one they can be built into a tiny diamond rod measuring only a few micrometres in length, like individual pearls on a necklace. Just like a tuning fork, this rod can then be made to vibrate - however, these vibrations are so small that they can only be described using quantum theory. It is through these vibrations that the silicon atoms can form a quantum-mechanical link to each other.
"Light is made from photons, the quantum of light. In the same way, mechanical vibrations or sound waves can also be described in a quantum-mechanical manner. They are comprised of phonons - the smallest possible units of mechanical vibration," explains Peter Rabl. As the research team has now been able to show using simulation calculations, any number of these quantum memories can be linked together in the diamond rod thanks to these phonons. The individual silicon atoms are "switched on and off" using microwaves. During this process, they emit or absorb phonons. This creates a quantum entanglement of different silicon defects, thus allowing quantum information to be transferred.
The road to a scalable quantum network
Until now it was not clear whether something like this was even possible: "Usually you would expect the phonons to be absorbed somewhere, or to come into contact with the environment and thus lose their quantum mechanical properties," says Peter Rabl. "Phonons are the enemy of quantum information, so to speak. But with our calculations, we were able to show that, when controlled appropriately using microwaves, the phonons are in fact useable for technical applications."
The main advantage of this new technology lies in its scalability: "There are many ideas for quantum systems that, in principle, can be used for technological applications. The biggest problem is that it is very difficult to connect enough of them to be able to carry out complicated computing operations," says Peter Rabl. The new strategy of using phonons for this purpose could pave the way to a scalable quantum technology.
Prof. Peter Rabl
Stadionallee 2, 1020 Vienna
Florian Aigner | EurekAlert!
How to control friction in topological insulators
14.10.2019 | Universität Basel
Nanoscale manipulation of light leads to exciting new advancement
14.10.2019 | University of New Mexico
A new research project at the TH Mittelhessen focusses on the development of a novel light weight design concept for leisure boats and yachts. Professor Stephan Marzi from the THM Institute of Mechanics and Materials collaborates with Krake Catamarane, which is a shipyard located in Apolda, Thuringia.
The project is set up in an international cooperation with Professor Anders Biel from Karlstad University in Sweden and the Swedish company Lamera from...
Superconductivity has fascinated scientists for many years since it offers the potential to revolutionize current technologies. Materials only become superconductors - meaning that electrons can travel in them with no resistance - at very low temperatures. These days, this unique zero resistance superconductivity is commonly found in a number of technologies, such as magnetic resonance imaging (MRI).
Future technologies, however, will harness the total synchrony of electronic behavior in superconductors - a property called the phase. There is currently a...
How do some neutron stars become the strongest magnets in the Universe? A German-British team of astrophysicists has found a possible answer to the question of how these so-called magnetars form. Researchers from Heidelberg, Garching, and Oxford used large computer simulations to demonstrate how the merger of two stars creates strong magnetic fields. If such stars explode in supernovae, magnetars could result.
How Do the Strongest Magnets in the Universe Form?
A hot, molten Earth would be around 5% larger than its solid counterpart. This is the result of a study led by researchers at the University of Bern. The difference between molten and solid rocky planets is important for the search of Earth-like worlds beyond our Solar System and the understanding of Earth itself.
Rocky exoplanets that are around Earth-size are comparatively small, which makes them incredibly difficult to detect and characterise using telescopes. What...
Scientists at the Max Planck Institute for Chemical Physics of Solids in Dresden, Princeton University, the University of Illinois at Urbana-Champaign, and the University of the Chinese Academy of Sciences have spotted a famously elusive particle: The axion – first predicted 42 years ago as an elementary particle in extensions of the standard model of particle physics.
The team found signatures of axion particles composed of Weyl-type electrons (Weyl fermions) in the correlated Weyl semimetal (TaSe₄)₂I. At room temperature,...
02.10.2019 | Event News
02.10.2019 | Event News
19.09.2019 | Event News
14.10.2019 | Physics and Astronomy
14.10.2019 | Earth Sciences
14.10.2019 | Health and Medicine