Quantum Science & Technology | 2021
Toward efficient correction of multiqubit measurement errors: pair correlation method
Abstract
Measurement errors limit the performance of near-term quantum computers and their potential for practical application. However they are partly correctable after a calibration step that requires, for a complete implementation on a register of n qubits, 2 n additional measurements. Here we introduce an approximate but efficient method for multiqubit measurement error characterization and mitigation requiring the classical processing of 2 n × 2 n matrices, but only O(4 k n 2) measurements, where k = O(1) is the number of qubits in a correlation volume. We demonstrate and validate the method on an IBM Q processor with registers of 4 and 8 superconducting qubits.