Error reduction

Error supression and error mitigation

Let's dive into two essential strategies to tackle errors in quantum computing: error suppression and error mitigation. Think of them as the dynamic duo working to keep your quantum computations on track.

Error supression

Error suppression is all about proactively reducing the likelihood of errors occurring during quantum computations. There are multiple ways in how to achieve this, examples include

  • Dynamical Decoupling (DD): This technique involves applying sequences of pulses to qubits to counteract environmental noise, effectively "decoupling" the qubits from their noisy surroundings (see here).

  • Gate Optimization: By fine-tuning quantum gates, we can minimize the introduction of errors during computations.

  • Noise-Aware Transpilation: This process adapts quantum circuits to the specific noise characteristics of the hardware, optimizing the circuit layout to reduce error rates.

Error mitigation

Even with the best proactive measures, some errors might slip through. That's where error mitigation comes in — it's about compensating for errors after they've occurred. Think of it as the cleanup crew ensuring your results are as accurate as possible. Known techniques include:

  • Readout Error Mitigation (REM): Account for known errors introduces by measurements through classical post-processing, ensuring the readout accurately reflects the qubits' states (see here).

  • Zero-Noise Extrapolation (ZNE): This method involves running the same quantum circuit at different noise levels and extrapolating the results to estimate what the outcome would be with zero noise.

  • Probabilistic Error Cancellation (PEC): PEC works by statistically combining results from various noisy circuits to cancel out errors, effectively reconstructing the ideal outcome.

These examples indicate that error-mitigation strategies typically improve the accuracy of quantum computations for the trade-off of increased circuit depth and longer execution times. This is because they often require additional measurements or circuit repetitions to gather the necessary data for mitigating errors.

Both, error mitigation and error supression, are essential tools in the quantum computing toolbox. They help us navigate the challenges posed by noise and errors, ensuring that we can extract meaningful results from quantum computations even in the presence of imperfections. A couple of these methods are already integrated into our quantum computing platform. So you can use them through IQM Resonance or our on-prem stations.