Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers Take First Look into the “Eye” of Majoranas

01.12.2016

Majorana fermions are particles that could potentially be used as information units for a quantum computer. An experiment by physicists at the Swiss Nanoscience Institute and the University of Basel’s Department of Physics has confirmed their theory that Majorana fermions can be generated and measured on a superconductor at the end of wires made from single iron atoms. The researchers also succeeded in observing the wave properties of Majoranas and, therefore, in making the interior of a Majorana visible for the first time. The results were published in the Nature journal npj Quantum Information.

Around 75 years ago, Italian physicist Ettore Majorana hypothesized the existence of exotic particles that are their own antiparticles. Since then, interest in these particles, known as Majorana fermions, has grown enormously given that they could play a role in creating a quantum computer.


Atomic force microscopy image of the end of a mono-atomic iron wire. The individual iron atoms are clear to see, as well as the “eye” of the Majorana fermions on the end.

University of Basel, Department of Physics

Majoranas have already been described very well in theory. However, examining them and obtaining experimental evidence is difficult because they have to occur in pairs but are then usually bound to form one normal electron. Ingenious combinations and arrangements of various materials are therefore required to generate two Majoranas and keep them apart.

Collaboration between theory and practice

The group led by Professor Ernst Meyer has now used predictions and calculations by theoretical physicists Professor Jelena Klinovaja and Professor Daniel Loss (from the Swiss Nanoscience Institute and the University of Basel’s Department of Physics) to experimentally measure states that correspond to Majoranas.

On a superconductor, the researchers evaporated single iron atoms with spin that, due to the row structure of the lead atoms, arrange themselves into a minute wire comprising one row of single atoms. The wires reached an astounding length of up to 70 nanometers.

Single Majoranas on the ends

The researchers examined these mono-atomic chains with the aid of scanning tunneling microscopy and, for the first time, with an atomic force microscope as well. Using the images and measurements, they found clear indications of the existence of single Majorana fermions on the ends of the wires under certain conditions and from a specific wire length on.

Despite the distance between them, the two Majoranas on the ends of the wires are still connected. Together, they form a new state extended across the whole wire that can either be occupied (“1”) or not occupied (“0”) by an electron. This binary property can then serve as the basis for a quantum bit (Qubit) and means that Majoranas, which are also very robust against a number of environmental influences, are promising candidates for creating a future quantum computer.

Predicted wavefunction measured

The researchers from Basel have not only shown that single Majoranas can be generated and measured at the ends of an iron wire, they also performed the first experiment to show that Majoranas are extended quantum objects with an inner structure, as predicted by their theory colleagues. Over an area of several nanometers, the measurements showed the expected wavefunction with characteristic oscillations and twofold decay lengths, which have now been made visible for the first time.

Original paper

Rémy Pawlak, Marcin Kisiel, Jelena Klinovaja, Tobias Meier, Shigeki Kawai, Thilo Glatzel, Daniel Loss, and Ernst Meyer
Probing atomic structure and Majorana wavefunctions in mono-atomic Fe chains on superconducting Pb surface
npj Quantum Information (2016), doi: 10.1038/npjqi.2016.35

Further information

Prof. Dr. Jelena Klinovaja, University of Basel, Department of Physics, tel +41 61 267 36 56, email: jelena.klinovaja@unibas.ch
Prof. Dr. Daniel Loss, University of Basel, Department of Physics, tel +41 61 267 37 49, email: daniel.loss@unibas.ch
Prof. Dr. Ernst Meyer, Univeristy of Basel, Department of Physics, tel +41 61 267 37 24, email:ernst.meyer@unibas.ch

Reto Caluori | Universität Basel
Further information:
http://www.unibas.ch

More articles from Physics and Astronomy:

nachricht NASA detects solar flare pulses at Sun and Earth
17.11.2017 | NASA/Goddard Space Flight Center

nachricht Pluto's hydrocarbon haze keeps dwarf planet colder than expected
16.11.2017 | University of California - Santa Cruz

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>