Nav: Home

Majorana runners go long range: New topological phases of matter unveiled

February 26, 2018

Researchers from Universidad Complutense de Madrid, MIT and Harvard University have discovered a mechanism that enhances the presence of Majorana particles at the edges of a topological superconductor, thanks to the presence of long-range magnetic interactions. Moreover, they have shown that it is possible to find new topological phases of matter by merging distant Majoranas into a new particle. This great achievement could have future applications for quantum technologies.

In a recent paper published in Physical Review Letters, these researchers explain how they improve the propagation of Majorana particles at the edge of a topological superconductor by exploring the nature of long-range interactions, and transforming the Majoranas into more stable quasiparticles.

The study of topological phases of matter has become a very active field of research, that is revolutionizing our understanding of nature. It has given rise to new materials like topological insulators, Weyl semimetals, and topological superconductors.

Topological superconductors are materials that, besides conducting electric current without dissipating energy as heat, they host unconventional particles known as Majorana fermions. It is unknown whether these particles exist in high energy physics, but remarkably, Majorana fermions appear as low energy excitations (quasiparticles) in certain materials.

Useful to build quantum computers

These particles are very exotic in condensed matter. They behave as their own antiparticle and have been proposed as building blocks of future topological quantum computers. A quantum computer uses certain remarkable properties of quantum physics to solve tasks and processes, that would otherwise be unsurmountable by conventional computers.

Nonetheless, these properties (such as quantum entanglement between tiny particles) are very sensitive to environmental interactions (decoherence). This is the main reason why the construction of quantum computers turns out to be a great challenge that is currently being tackled by research labs and companies all over the world. The Majorana fermions that appear in topological superconductors are much more robust than other conventional particles, which would allow to build such novel computers.

The existence of Majorana fermions had been already proven in earlier works: chains of magnetic impurities placed on top of a superconductor substrate have shown that long-range magnetic interactions between electrons appear very naturally in these materials.

According to the authors of this publication, these interactions are very similar to the one between two magnets that feel attraction or repulsion to one another. In this case, it would be the magnetic moments of the electrons that interact with each other instead of the magnets.

However, it remained unknown what the effect of these magnetic interactions was over the properties of superconducting materials. This is precisely what this research work has solved.

Merging of Majorana particles

The researchers of this collaboration have found cases where the long-range effects of the magnetic interactions were so strong, that two distant Majorana fermions merged into a non-local topological quasiparticle.

This surprising effect could be used to store quantum information in a non-degenerate system (i.e. two-level systems with different energy), but with extra protection against external noise, caused by decoherence, or the loss of quantum effects.

These findings represent a great leap towards the understanding of the role of long-range magnetic interactions in the realm of topological superconductors. Moreover, these results will spark generation of novel topological phases of mater, widening their current applications in spintronics, quantum memories and computers, and other related fields.
-end-
Reference

Chiral Topological Superconductors Enhanced by Long-Range Interactions, O. Viyuela, L. Fu, M. A. Martin-Delgado, Phys. Rev. Lett. 120, 017001 (2018)

QUITEMAD+

Related Energy Articles:

Mandatory building energy audits alone do not overcome barriers to energy efficiency
A pioneering law may be insufficient to incentivize significant energy use reductions in residential and office buildings, a new study finds.
Scientists: Estonia has the most energy efficient new nearly zero energy buildings
A recent study carried out by an international group of building scientists showed that Estonia is among the countries with the most energy efficient buildings in Europe.
Mapping the energy transport mechanism of chalcogenide perovskite for solar energy use
Researchers from Lehigh University have, for the first time, revealed first-hand knowledge about the fundamental energy carrier properties of chalcogenide perovskite CaZrSe3, important for potential solar energy use.
Harvesting energy from walking human body Lightweight smart materials-based energy harvester develop
A research team led by Professor Wei-Hsin Liao from the Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong (CUHK) has developed a lightweight smart materials-based energy harvester for scavenging energy from human motion, generating inexhaustible and sustainable power supply just from walking.
How much energy do we really need?
Two fundamental goals of humanity are to eradicate poverty and reduce climate change, and it is critical that the world knows whether achieving these goals will involve trade-offs.
New discipline proposed: Macro-energy systems -- the science of the energy transition
In a perspective published in Joule on Aug. 14, a group of researchers led by Stanford University propose a new academic discipline, 'macro-energy systems,' as the science of the energy transition.
How much energy storage costs must fall to reach renewable energy's full potential
The cost of energy storage will be critical in determining how much renewable energy can contribute to the decarbonization of electricity.
Energy from seawater
A new battery made from affordable and durable materials generates energy from places where salt and fresh waters mingle.
Shifts to renewable energy can drive up energy poverty, PSU study finds
Efforts to shift away from fossil fuels and replace oil and coal with renewable energy sources can help reduce carbon emissions but do so at the expense of increased inequality, according to a new Portland State University study
Putting that free energy around you to good use with minuscule energy harvesters
Scientists at Tokyo Tech developed a micro-electromechanical energy harvester that allows for more flexibility in design, which is crucial for future IoT applications.
More Energy News and Energy Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at Radiolab.org/donate.