The core technology of the Willow chip lies in its remarkable quantum error - correction capabilities. It employs an error - correction scheme known as the "surface code", which can encode multiple physical qubits into a single logical qubit. Through this encoding method, even if some qubits malfunction, the overall computational result remains accurate. More importantly, the Willow chip has successfully surpassed a crucial threshold in quantum error correction. This means that as the number of qubits increases, the error rate does not rise but rather decreases exponentially.
Google tested increasingly larger arrays of physical qubits, expanding from a 3x3 encoded qubit grid to a 5x5 grid and then to a 7x7 grid. Each time the grid size was increased, the error rate was halved. Manufactured in Google's own dedicated superconducting chip manufacturing facility, the Willow chip enables better control over manufacturing process parameters, resulting in improved yield and consistency. This breakthrough in quantum error correction with the Willow chip could potentially pave the way for more reliable and powerful quantum computers in the future, opening up new possibilities for scientific research, complex simulations, and solving problems that are currently intractable for classical computers.
