Researchers at RIKEN in Japan have made a big step forward toward the development of large-scale quantum computing by demonstrating error correction in a silicon-based quantum computing system that consists of three qubits. This finding has the potential to contribute to the development of practical quantum computers.
Because quantum computers hold the potential to address significant problems that can’t be tackled using traditional computers, this topic is now receiving a lot of attention from researchers. They utilise the superposition states of quantum physics rather than the plain 1 or 0 binary bits that are inherent in ordinary computers. Due to the fundamentally unusual way that they are constructed, however, they are extremely vulnerable to environmental noise as well as other challenges, such as decoherence, and thus require error correction in order to do precise computations.
The selection of systems that have the potential to serve as the most effective “qubits,” or the fundamental units that are required for quantum computing, is a key challenge in the modern era. Every potential solution has a set of benefits and drawbacks that are unique to themselves. Popular systems of today include superconducting circuits and ions. These systems have the advantage of having some form of error correction proved, which enables them to be used in real-world applications, albeit on a more limited scale.
The development of silicon-based quantum technology, which has only very recently begun, is known to offer an advantage in the sense that it makes use of a semiconductor nanostructure that is comparable to what is frequently used to integrate billions of transistors on a compact chip, and as a result, it potentially benefits from the manufacturing technology that is already in use. However, one of the most significant issues that arises from the use of silicon-based technology is the absence of technology for incorrect connection. Control over two qubits has been proven in the past by researchers, but this is insufficient for error correction, which calls for a system consisting of three qubits.
In the most recent study, which was carried out by researchers at the RIKEN Center for Emergent Matter Science and the RIKEN Center for Quantum Computing, the group demonstrated full control of a three-qubit system, which is one of the largest qubit systems in silicon. As a result, they were able to provide a prototype for the very first time of quantum error correction in silicon. They were able to accomplish this by constructing a Toffoli-type quantum gate with three qubits.
According to Kenta Takeda, the first author of the paper, “The idea of implementing a quantum error-correcting code in quantum dots was proposed about a decade ago, so it is not an entirely new concept. However, a series of improvements in materials, device fabrication, and measurement techniques allowed us to succeed in this endeavor.” This was the first time that a quantum error-correcting code had been successfully implemented in quantum dots. We are overjoyed to have been successful in this endeavor.
The head of the study team, Seigo Tarucha, has stated that “our next step will be to scale up the system.” We believe that the next stage is to increase our scale. To do this, it would be ideal to collaborate with groups within the semiconductor industry that are able to produce silicon-based quantum devices on a big scale.