Title:
Noise Mitigation Techniques in Near-Term Quantum Computers
Abstract:
Current quantum computers, known as Noisy Intermediate-Scale Quantum (NISQ)
devices, suffer from significant hardware-induced errors. This report provides a
concise overview of leading noise mitigation techniques used to improve computation
accuracy without requiring full quantum error correction.
1. Introduction
Quantum computers promise exponential speedups for certain problems, but today's
devices are limited by decoherence, gate errors, and readout noise. As full-scale
error correction remains infeasible for NISQ systems, alternative error mitigation
strategies are vital for useful computation.
2. Common Noise Mitigation Techniques
Zero-Noise Extrapolation (ZNE): Artificially amplifies noise and fits an
extrapolation to estimate the zero-noise result.
Probabilistic Error Cancellation: Involves applying a quasi-probability
distribution over noisy operations to statistically cancel out known noise effects.
Measurement Error Mitigation: Uses calibration matrices to correct for bias in
measurement readouts, especially in multi-qubit systems.
Clifford Data Regression: Combines classical shadow techniques with Clifford
circuits to infer noise-free observables.
3. Case Study: Variational Quantum Eigensolver (VQE)
When applied to a hydrogen molecule using IBM’s 5-qubit quantum computer, zero-
noise extrapolation improved energy estimation accuracy by 40%, bringing results
closer to exact diagonalization. The experiment demonstrated how even basic
mitigation can significantly improve practical performance.
4. Conclusion
While not a substitute for full error correction, noise mitigation techniques
extend the practical utility of NISQ devices. Future developments may combine these
methods with hardware improvements to push the boundaries of feasible quantum
applications.