Researchers and engineers from QuTech and Eindhoven University of Technology developed Majorana molecules and measured their properties (A new method for Majorana search in short nanowires) with great control. These Majoranas are the so-called “poor man’s Majoanas” based on binary dots and nanowires, which can be extended to large numerical values and the behavior of Majorana is flexible. Majorana particles are one of many promising candidates for stable quantum bits, the building block of quantum computers. The researchers published their findings in Nature.
Quantum computing is a revolutionary technology, capable of solving certain problems faster than classical computers. This is because they use quantum bits, or qubits, which can represent both 0 and 1 at the same time. This allows quantum computers to perform many calculations simultaneously. The implementation of quantum computers and qubits has great potential in various fields, including drug discovery, money laundering and cryptography.
The Majorana thing
“Majorana particles can be converted into qubits and attract attention because of their unique properties,” says first author Tom Dvir, a postdoctoral researcher at QuTech, the center for quantum technology at TU Delft and owned by TNO. He continues: “Unlike normal qubits, which are based on the properties of individual particles such as electrons, qubits based on Majorana particles often accept certain types of quantum errors, which is a major challenge in the development of scalable quantum computers.
His colleague and first author Guanzhong Wang adds: “The desirable properties of Majorana molecules, and their unique nature that allows for new scientific observations, have stimulated a great deal of research effort. , first through education and later through industry. Until now, the research was mainly based on material synthesis, aiming to engineer the food properties of the material so that the device was made so that they were immediately taken when the temperature was low.
This new method emphasizes electrical control, which means that we see and adjust the device at a low temperature to create conditions for the Majoranas to emerge.
Strings of quantum dots to separate electron halves
Wang: “Unlike regular qubits, Majoranas always appear in pairs, and each pair forms a virtual electron. This means that the Majorana phase can reside at one end of the nanowire and the second phase at the other end. To manipulate the Majorana particle, we need to affect both ends at the same time. This makes them ideal for quantum computing because if one part is affected by sound, the other half will not be harmed.
The researchers start by creating two quantum dots in close proximity, separated by a thin semiconductor/superconductor nanowire. Quantum dots are electrically connected to each other in two ways. The first is the jump of an electron between the two points. The second involves a pair of electrons entering and leaving the semiconductor/superconductor nanowire simultaneously. The researchers presented a new method to control the two processes directly, the key to the establishment of Majorana.
Future work
“Currently, we work with a simple version of Majoranas,” Dvir explains, “using only binary numbers. Our main goal is to have more points, maybe even a few five, so that the electron halves are separated in many places. The more Majorana particles are separated, the better the qubits are protected from noise.
“The difficulty of adding points to the device should increase linearly rather than vertically. In fact, we can adjust each point individually, which makes it easier for us to decide on a good arrangement. »
Research Director Leo Kouwenhoven: “Looking forward, there are two main goals for the future. The first is to construct a complete topological Majorana based on the poor man’s Majorana in this work. The second goal is to use these Majoranas to create qubits. This will require multiple copies of the system and additional maintenance.
