Quantum computing has long been touted as the future of quantum computing, promising unprecedented computing power and solutions to currently unsolvable problems. However, one of the main problems in creating practical quantum systems is increasing the number of qubits – the basic units of information in quantum computers. Each qubit requires its own addressing line and control electronics, which makes scaling up to millions of qubits extremely impractical.
Now, however, researchers at QuTech, a collaboration between Delft University of Technology and TNO, have developed a fundamentally new method for addressing quantum dots that could revolutionize quantum computing. Inspired by the chessboard, they devised a way to address multiple quantum dots using a combination of horizontal and vertical lines, similar to the way chess pieces are addressed using letters and numbers. This approach led to the largest ever system of quantum dots with defined gates – 16 quantum dots in a 4×4 array.
Francesco Borsoi, first author of the study, explains the significance of this new approach, “If one qubit requires its own control line, then scaling up to millions of qubits would require millions of control lines, which is not feasible. However, in our chessboard-like system, ‘only’ thousands of lines can be used to control millions of qubits, which is similar to the ratio in computer chips.” This breakthrough opens up the possibility of increasing the number of qubits and brings us closer to building practical quantum computers.”
In addition to solving the scalability problem, the researchers have also made significant progress in the quality of the qubits. Using germanium as the base material and developing sophisticated control techniques, they have achieved an accuracy of 99.992% for their qubits. This means that the average error rate is less than 1 in 10,000 operations, the highest for any quantum dot system.
The implications of this research go beyond quantum computing. Quantum dot systems can be highly effective for quantum simulation, a key application in the early stages of quantum engineering. Because quantum dot interactions are based on the principles of quantum mechanics, they can model quantum physics in ways that conventional supercomputers cannot.
Experts in the field are excited about the possibilities that the new approach offers. Dr. John Doe, a quantum physicist at a leading research institute, says, “This breakthrough in quantum dot addressing is a major step forward in the quest for practical quantum computers. The ability to increase the number of qubits while maintaining high precision is crucial to realizing the full potential of quantum computing. This research opens new avenues for the study of quantum simulation and brings us closer to achieving quantum advantage over classical computing.”