Protecting quantum entanglement from leakage and qubit errors via repetitive parity measurements.

ABSTRACT: Protecting quantum information from errors is essential for large-scale quantum computation. Quantum error correction (QEC) encodes information in entangled states of many qubits and performs parity measurements to identify errors without destroying the encoded information. However, traditional QEC cannot handle leakage from the qubit computational space. Leakage affects leading experimental platforms, based on trapped ions and superconducting circuits, which use effective qubits within many-level physical systems. We investigate how two-transmon entangled states evolve under repeated parity measurements and demonstrate the use of hidden Markov models to detect leakage using only the record of parity measurement outcomes required for QEC. We show the stabilization of Bell states over up to

SUBMITTER: Bultink CC 

PROVIDER: S-EPMC7083610 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature