Discovered the Majorana Particles in Gold by MIT Team

Figure | In this study, the conceptual image of the Majorana particles on the "gold" surface. (Source: stock images)

MIT team discovers Majorana particles in gold for the first time, helping to develop highly fault-tolerant quantum computers. A physicist at the Massachusetts Institute of Technology has recently successfully observed the Majorana particles on the surface of a common metal-"gold" (yes, gold of gold), proving its existence. This opens up new possibilities for the development of high-fault-tolerant quantum computers. The research was published in the Proceedings of the National Academy of Sciences (PNAS). Fermi particles are basic particles in physics. All particles with a spin of 1/2, such as electrons, protons and neutrons, are actually classified as fermi particles. The concept of Fermi particles was first proposed by the British physicist Paul Dirac, who believed that every Fermi particle has an antiparticle in the universe.

Later, in 1937, the Italian physicist Ettore Majorana further developed the theory, thinking that there are some particles in the Fermi particles, which are what we call the Majorana particles here, which is contrary to Particles are indistinguishable in nature. This later ignited a wave of searching for Majorana particles in the physics community, and even continued until now. There have been previous theories that neutrinos are a type of Majorana particles, but there is no empirical evidence. In addition, there are also theories that the Majorana particles may be observed in solids under some special conditions. The MIT research provides empirical evidence.

In this study, by designing and cultivating nano-scale gold filaments grown on the superconducting material "vanadium", the electrical conductivity was detected on the upper surface of the gold filament to confirm the superconducting area of ​​the material, and then the distribution on these gold filaments was observed. "Magnetic" miniature Europium Sulfide (Europium Sulfide, whose magnetic properties provide the magnetic field that generates the Majorana particles) "island". Finally energy characteristic signal successfully detected in the energy spectrum near zero representing "the presence of Majorana particles" 

Jagadeesh Moodera, a senior researcher at the Massachusetts Institute of Technology, said: "For a long time, we have tried every means to actually detect the existence of Majorana particles in experiments, and now we have done it, and proved that they can a stable way to easily expand. " The co-author of the paper, Patrick Lee of the Massachusetts Institute of Technology, believes that they have successfully discovered and explored the "expansibility of the Majorana particle" to a certain extent, the next research direction is quantum computer Qubit development.

In the research and development of quantum computers, some people had previously put forward the idea of ​​"taking the Majorana particles as qubits", that is, a quantum bit is composed of a pair of Majorana particles, and the "noise" that may appear in the calculation It will only affect one of the two Majorana particles, so that the other works normally, and the quantum computer is protected from "noise" and continues to calculate. However, although people have been working in the past to find the Majorana particles that may be generated by the splitting of particles caused by superconducting materials in semiconductors or superconducting materials. Just before this publication, still It is very difficult to enlarge the size of this superconducting material during the growth of the material in the ratio required for quantum calculations, in order to reliably observe and use the Majorana particles.

Jagadeesh Moodera said: "In addition to the particles does found Majorana, Another noteworthy point is that our preparation method for the material is more traditional and generated qubit based semiconductor in a more stable manner, The material itself is just a 'sandwich' structure that places gold between the ferromagnet and the superconductor, which also makes it relatively more likely to be commercialized in terms of cost . " The co-author of the paper, a former postdoctoral fellow at the Massachusetts Institute of Technology, and now working at the University of California, Riverside, Peng Wei believes that the next direction of research may be mainly on how to control and use the Majorana particles. Peng Wei said: "It is very important to actually observe the Majorana particles in a more versatile platform such as common metals, which lays the foundation for us to use them in the future. One point, the next goal of the research is to consider how to build qubits with Majorana particles, and we have some ideas for this. "
Reference: https://news.mit.edu/2020/first-majorana-fermion-metal-quantum-computing