An alternative method to seek the elusive Majorana particles was conceived theoretically around 15 years ago. However, no one had performed the experiment until now. Physicist Jianfeng Ge and his colleagues from the Allan laboratory of the Leiden Institute of Physics have performed the first measurements successfully.
Image Credit: S.Gvozd/Shutterstock.com
There are a few methods by which physicists can search for Majorana quasiparticles. The main method relies on conductivity measurements. However, that has not offered the definitive outcomes researchers believed. Hence, Ge searched for a new method.
Back when I was at Harvard, I talked to my colleague Eugene Demler about shot noise measurements that should be able to identify majoranas. He had theorized this fifteen years ago, but no one ever tried it. I thought it was promising so I convinced Milan Allan from the Quantum Matter group to do it. And now we have our first results.
Jianfeng Ge, Physicist, Leiden University
The Hunt for Exotic Majorana Particles
Majoranas are hypothetical particles that are their own antiparticles. This makes them different from any of the particles that are known already, and identifying them could result in new breakthroughs in physics. Ge is actually searching for Majorana quasiparticles in quantum matter.
This is a huge number of electrons that act just like a Majorana particle. One of the reasons researchers wish to determine Majoranas is their ability to revolutionize quantum computing. At present, the qubits that are utilized in quantum computers are not highly stable and prone to errors. Majorana qubits can be the long-awaited cornerstone for fault-tolerant quantum computers.
Paving the Way for Ultimate Proof of Majoranas
The Majorana particles have been anticipated to live in the vortices of an iron-based superconductor that has been studied by Ge.
These vortices are only a few nanometers in size. Only in recent years technology has advanced to the point where we can measure at this small scale. We are the first ones in the world to do this experiment. I find that very exciting.
Jianfeng Ge, Physicist, Leiden University
Ge added, “We nailed down the origin of the quasiparticles within two possible explanations, one of which is majoranas. These measurements pave the way for ultimate proof of Majoranas. We learned a lot and know how to improve the setup for future measurements.”
At this stage, the outcomes are very promising.
I share the enthusiasm about the potential for quantum computing but it is not what excites me most about this research. What drives me is curiosity. I want to understand the fundamental principles of the physics itself.
Jianfeng Ge, Physicist, Leiden University
“It will be a long journey to find the ultimate proof for Majorana particles, let alone develop applications like a quantum computer. But with this experiment we know what to do next. It will not be easy and take a lot of technical instrument development, but I am proud that we are one step closer to finding Majoranas.”
Journal Reference
Ge, J-F., et al. (2023) Single-electron charge transfer into putative Majorana and trivial modes in individual vortices. Nature Communications. doi.org/10.1038/s41467-023-39109-w.