Toshiba Corporation has announced a significant advance in quantum computing technology with the development of the double transmon coupler, an innovation aimed at improving the performance of superconducting quantum computers. This breakthrough, achieved in collaboration with the Japanese research institute RIKEN, has reached a two-qubit gate fidelity of 99.90%, a world-class standard that enhances precision in quantum operations.
Fidelity, a key indicator in quantum computing, measures how close an operation is to its ideal, with higher values indicating greater accuracy. According to Toshiba, this achievement promises significant advancements in practical applications, such as carbon neutrality and the development of new drugs, by improving the efficiency and scalability of quantum systems.
Cutting-edge technology for quantum gates
The double transmon coupler is an adjustable device that connects two superconducting qubits, allowing for rapid and precise quantum gate operations. In experimental tests, Toshiba and RIKEN managed to reduce residual coupling to just 6 kHz and achieved a gate operation time of 48 nanoseconds, a crucial balance to minimize errors and maintain the stability of quantum states.
The qubits used are fixed-frequency transmons, known for their structural simplicity and stability, making them easier to manufacture and ensuring greater viability for industrial scales.
Impact and key features
This development addresses fundamental challenges in quantum computing, such as the need for longer coherence times and the suppression of residual couplings. According to published data, the qubits achieved sufficient coherence times (T1 and T2) to guarantee stable and precise operations.
- Coherence: T1 times of up to 230 μs and T2 times of 360 μs in the qubits, indicators of prolonged stability.
- Flexibility: Adjustments in the external magnetic flux allow control over the coupling strength between qubits, maximizing operational efficiency.
- Sustained performance: During 12 hours of testing, the fidelity of the two-qubit gates remained at an average of 99.90%, placing it among the best results globally.
Towards a future of practical quantum computing
This advancement has been published in the prestigious journal Physical Review X and is part of the Q-LEAP flagship project of Japan’s Ministry of Education, Culture, Sports, Science, and Technology. Toshiba and RIKEN’s next goal is to increase the fidelity of quantum gates to 99.99% and develop scalable technologies for large-scale quantum systems.
The development of these systems is key to addressing complex problems that are beyond the reach of classical computing, consolidating Japan’s role as a leader in quantum research.
One step closer to advanced quantum computing
The success of the double transmon coupler highlights the potential of superconducting quantum computers in strategic sectors, from energy sustainability to personalized medicine. Toshiba and its partners continue to advance the design of technologies that promise to transform not only science but also the way we tackle the most challenging global issues.
Source: Toshiba