In collaboration with researchers from Harvard University, researchers from the University of Würzburg have made an important step on the road to topological quantum computers. Now, they present their findings in the renowned scientific journal Nature.
Majorana particles are very peculiar members of the family of elementary particles. First predicted in 1937 by the Italian physicist Ettore Majorana, these particles belong to the group of so-called fermions, a group that also includes electrons, neutrons and protons. Majorana fermions are electrically neutral and also their own anti-particles. These exotic particles can, for example, emerge as quasi-particles in topological superconductors and represent ideal building blocks for topological quantum computers.
Going to two dimensions
On the road to such topological quantum computers based on Majorana quasi-particles, physicists from the University of Würzburg together with colleagues from Harvard University (USA) have made an important step: Whereas previous experiments in this field have mostly focused on one-dimensional systems, the teams from Würzburg and Harvard have succeeded in going to two-dimensional systems.
In this collaboration, the groups of Ewelina Hankiewicz (Theoretische Physik IV) and Laurens Molenkamp (Experimentelle Physik III) from the University of Würzburg teamed up with the groups of Amir Yacoby and Bertrand Halperin from Harvard University. Their findings are presented in the current issue of the scientific journal Nature.
Two superconductors can simplify matters
Realizing Majorana fermions is one of the most intensely studied topics in condensed matter physics,“ Ewelina Hankiewicz says. According to her, previous realizations have usually focused on one-dimensional systems such as nanowires. She explains that a manipulation of Majorana fermions is very difficult in these setups. It would therefore require significant efforts to make Majorana fermions in these setups eventually applicable for quantum computing.
In order to avoid some of these difficulties, the researchers have studied Majorana fermions in a two-dimensional system with strong spin-orbit coupling. „The system we investigate is a so-called phase-controlled Josephson junction, that is, two superconductors that are separated by a normal region,“ Laurens Molenkamp explains. The superconducting phase difference between the two superconductors provides an additional knob, which makes an intricate fine-tuning of the other system parameters at least partially unnecessary.
Important step towards an improved control
In the material studied, a mercury telluride quantum well coupled to superconducting thin-film aluminium, the physicists observed for the first time a topological phase transition which implies the appearance of Majorana fermions in phase-controlled Josephson junctions. The setup realized experimentally here constitutes a versatile platform for the creation, manipulation and control of Majorana fermions, which offers several advantages compared to previous one-dimensional platforms. According to Hankiewicz, „this is an important step towards an improved control of Majorana fermions.“ The proof of concept of a topological superconductor based on a two-dimensional Josephson junction opens up new possibilities for the research on Majorana fermions in condensed matter physics. In particular, several constraints of previous realizations of Majorana fermions can be avoided.
Potential revolution in computer technology
At the same time, an improved control of Majorana fermions represents an important step towards topological quantum computers. Theoretically, such computers can be significantly more powerful than conventional computers. They thus have the potential to revolutionize computer technology.
Next, the researchers plan to improve the Josephson junctions and move towards junctions with narrower normal regions. Here, more localized Majorana fermions are expected. They further study additional possibilities of manipulating Majorana fermions, for example, by using other semiconductors.
Learn more: Computing faster with quasi-particles
The Latest on: Topological quantum computers
via Google News
The Latest on: Topological quantum computers
- Topological Quantum Computing Market Future Prospects 2025 | Microsoft, IBM, Google, D-Wave Systems, Airbuson November 28, 2019 at 4:02 am
Nov 28, 2019 (HTF Market Intelligence via COMTEX) -- Global Topological Quantum Computing Market Size, Status and Forecast 2019-2025 is latest research study released by HTF MI evaluating the market, ...
- Physicists capture first footage of quantum knots unraveling in superfluidon November 15, 2019 at 12:10 pm
For now, at least, quantum knots remain a laboratory curiosity, but the research might have bearing on ongoing research into building topological quantum computers. Such a device would braid qubits in ...
- Microsoft’s Hunt for a Topological Quantum Computer Qubiton November 11, 2019 at 4:00 pm
Microsoft has been working on a qubit technology called a topological qubit that it expects will deliver benefits from quantum computing technology that today are mostly just a promise. After spending ...
- The Deal w/ Topological Quantum Computingon November 9, 2019 at 1:55 am
Logically it is very simple to understand the concept behind the functioning of a Topological Quantum Computer. You basically start by preparing Quantum States (Values of your Variables) by creating ...
- For faster quantum computing, Microsoft builds a better qubiton November 7, 2019 at 1:02 pm
But Microsoft expects progress of its own by redesigning the core element of quantum computing, the qubit. Microsoft has been working on a qubit technology called a topological qubit that it expects ...
- Inside Azure Quantum: Microsoft's plan to deliver quantum resources to developerson November 5, 2019 at 5:44 am
In 2018, the company announced the development of a noise-resistant topological qubit ... For all of the excitement that follows the field of quantum computing, there has been to date few practical ...
- Laser pulses create topological state in grapheneon November 5, 2019 at 4:32 am
Discovering ways to control the topological aspects of quantum materials is an important research frontier because it can ... "The ultrafast appearance of this effect holds great potential for the ...
- Microsoft Is Taking Quantum Computers to the Cloudon November 4, 2019 at 6:08 am
Quantum computers are built from unusual devices called qubits ... Microsoft is betting on a so-far-theoretical version of the crucial device called a topological qubit, predicted to be more stable ...
- Global Topological Quantum Computing Market 2019 Market Size, Share, Trends, Growth, Insights and Key Players, Forecast Research Report 2025on October 16, 2019 at 7:57 pm
Oct 17, 2019 (The Expresswire) -- 2019 Research Report on Global Topological Quantum Computing Market is a professional and comprehensive report on the Topological Quantum Computing industry. The ...
- He Built the Xbox—Can He Make a Microsoft Product Out of Quantum Computing?on October 9, 2019 at 12:39 pm
A theory known as topological quantum computing predicts that data written into the particles, by a device called a topological qubit, will be resilient to perturbations that would wipe out anything ...
via Bing News