Understanding the effects of leakage in superconducting quantum error detection circuits

Understand

The majority of quantum error detection and correction protocols assume that the population in a qubit does not leak outside of its computational subspace.

• For many existing approaches, however, the physical qubits do possess more than two energy levels and consequently are prone to such leakage events.
• Analyzing the effects of leakage is therefore essential to devise optimal protocols for quantum gates, measurement, and error correction.
• In this work, we present a detailed study of leakage in a two-qubit superconducting stabilizer measurement circuit.