Coupling atomic spins in diamonds to microwave resonators could lead to new quantum technologies. Researchers at the Vienna University of Technology (TU Wien) have now managed to dramatically prolong the time these systems can store information
The electronics we use for our computers only knows two different states: zero or one. Quantum systems on the other hand can be in different states at once, they can store a superposition of "zero" and "one".
This phenomenon could be used to build ultrafast quantum computers, but there are several technological obstacles that have to be overcome first. The biggest problem is that quantum states are quickly destroyed due to interactions with the environment. At TU Wien (Vienna), scientists have now succeeded in using a protection effect to enhance the stability of a particularly promising quantum system.
A Quantum Computer Made of Two Systems
There are various concepts for possible quantum computers. "What we use is a hybrid system of two completely different quantum technologies", says Johannes Majer. Together with his team, he couples microwaves and atoms, investigating and building a new type of quantum memory.
The theorists Dmitry Krimer and Stefan Rotter developed a theoretical model describing the complex dynamics in such hybrid quantum systems.
In a microwave resonator, photons are created. They interact with the spin of nitrogen atoms, which are built into a diamond. The microwave resonator can be used to quickly transport quantum information.
The atomic spins in the diamond can store it – at least for a period of several hundred nanoseconds, which is long compared to the time scale on which photons move in the microwave resonator.
"All nitrogen atoms are completely identical. But when they are placed in slightly different surroundings, they have slightly different transition frequencies", says Stefan Putz, PhD-student at Vienna University of Technology. The atomic spins behave like a room full of pendulum clocks. Initially they may oscillate in sync, but as they can never be precisely identical, they eventually lose their rhythm, creating random noise.
Coupling Causes Order
"By creating a strong coupling between the atomic spins and the resonator, it is possible to dramatically prolong the time during which the spins oscillate in strict time – if their energy levels obey the right distribution", says Dmitry Krimer. The atomic spins do not directly interact with each other, but the mere fact that they are collectively coupled to the microwave resonator prevents them from changing into a state in which they cannot be used for processing quantum information any longer. This protection effect considerably enhances the duration in which quantum information can be read out from the atomic spins.
"Improving the quantum coherence time with this cavity protection effect opens up many promising applications for our hybrid quantum system", says Johannes Majer. The paper has now been published in Nature Physics.
Dr. Johannes Majer
Institute for Atomic and Subatomic Physics
Stadionallee 2, 1020 Wien
Florian Aigner | Eurek Alert!
Hubble observes one-of-a-kind star nicknamed 'Nasty'
22.05.2015 | NASA/Goddard Space Flight Center
Basel Physicists Develop Efficient Method of Signal Transmission from Nanocomponents
22.05.2015 | Universität Basel
Physicists have developed an innovative method that could enable the efficient use of nanocomponents in electronic circuits. To achieve this, they have developed a layout in which a nanocomponent is connected to two electrical conductors, which uncouple the electrical signal in a highly efficient manner. The scientists at the Department of Physics and the Swiss Nanoscience Institute at the University of Basel have published their results in the scientific journal “Nature Communications” together with their colleagues from ETH Zurich.
Electronic components are becoming smaller and smaller. Components measuring just a few nanometers – the size of around ten atoms – are already being produced...
Development and implementation of an advanced automobile parking navigation platform for parking services
To fulfill the requirements of the industry, PolyU researchers developed the Advanced Automobile Parking Navigation Platform, which includes smart devices,...
The world's first electrical car and passenger ferry powered by batteries has entered service in Norway. The ferry only uses 150 kWh per route, which...
On Tuesday, 19 May 2015 the research icebreaker Polarstern will leave its home port in Bremerhaven, setting a course for the Arctic. Led by Dr Ilka Peeken from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) a team of 53 researchers from 11 countries will investigate the effects of climate change in the Arctic, from the surface ice floes down to the seafloor.
RV Polarstern will enter the sea-ice zone north of Spitsbergen. Covering two shallow regions on their way to deeper waters, the scientists on board will focus...
Nanoengineers at the University of California, San Diego developed a gel filled with toxin-absorbing nanosponges that could lead to an effective treatment for skin and wound infections caused by MRSA (methicillin-resistant Staphylococcus aureus), an antibiotic-resistant bacteria. This "nanosponge-hydrogel" minimized the growth of skin lesions on mice infected with MRSA - without the use of antibiotics. The researchers recently published their findings online in Advanced Materials.
To make the nanosponge-hydrogel, the team mixed nanosponges, which are nanoparticles that absorb dangerous toxins produced by MRSA, E. coli and other...
20.05.2015 | Event News
18.05.2015 | Event News
12.05.2015 | Event News
22.05.2015 | Materials Sciences
22.05.2015 | Information Technology
22.05.2015 | Materials Sciences