The continuous path from error mitigation to fault-tolerant quantum computing

Key takeaways:

• Quantum error mitigation and error correction are both extending the path to useful quantum computing before full fault-tolerant quantum computing, with emerging error-correction techniques already demonstrating ~10x lower effective error rates than the underlying physical hardware.
• Hybrid error-correcting techniques can improve reliability while reducing the resources required for useful computations. Current results show 63x reduction in the inferred sampling overhead compared to error mitigation techniques alone.
• Conditional methods enable partially fault-tolerant architectures to reach universal quantum computation while avoiding some of the significant resource overheads of traditional fault-tolerant approaches.
• Hierarchical codes provide a route to substantially reduced error rates without the need to build greater complexity into the chip, relaxing the physics and engineering requirements for reaching trillions of operations.
• IBM Quantum Platform and Qiskit provide quantum information scientists access to every layer of the stack, from pulse-level capabilities through compilation and execution, enabling new approaches to quantum error correction and device characterization.