Automated Flag Qubit Insertion for Reliable Quantum Circuit Output
Nikita Acharya, Samah Mohamed Saeed · 2021
Quantum circuit compilers play an important role in mitigating errors of quantum circuits executed on Noisy Intermediate-Scale Quantum (NISQ) computers. The compiler maps the quantum algorithm into a physical quantum circuit that satisfies the physical constraints of NISQ architecture. However, the reliability of NISQ computers is still very challenging. In this work, we design a new class of quantum test circuits using flag qubits based on error propagation. Furthermore, we automate the test point insertion. Our approach can detect errors at different points in the circuit to assess its output reliability. The goal is to select a qubit allocation that improves the quantum circuit output fidelity. We show the effectiveness of our approach using an IBM quantum computer and a noisy simulator.