Running complex algorithms on quantum computing hardware requires a new approach, involving logical qubits. Each logical qubit is a collection of hardware qubits linked to detect and correct errors. However, adding more hardware qubits increases the chance of errors, creating a challenging balance. Several companies have demonstrated hardware with low enough error rates for logical qubits to surpass the breakeven point, where adding more qubits improves performance. Yet, the improvement isn’t dramatic, making it impractical to achieve the necessary error rates for complex algorithms.
On Monday, Quantinuum announced that its hardware can scale well beyond the breakeven point, with each step up in logical qubit size improving performance by over ten times. Understanding this involves delving into error correction codes, which consist of entangled qubits used to measure and correct errors. These codes have various properties, including the number of hardware qubits required, the number of logical qubits they host, and the distance, a measure of how many errors can occur before failure.
The journey to practical quantum computing is fraught with such paradoxes. While the technology is advancing, the complexity of the systems needed for real-world applications remains daunting. The question remains: will the patience of humanity keep pace with the quantum leap?







