EAGER: QIA: A quantum algorithm for detecting quantum information leakage in qubit systems

In quantum computers, information is encoded in quantum bits, that is, qubits. Ideally a qubit is a two-level quantum system, representing the logical states "0" and "1". In the two leading quantum computing platforms, superconducting flux qubit and trapped ions, quantum information encoded in the qubit is prone to leakage.

As a consequence, information leakage is one of the main sources of errors that affect our ability to perform successful computing on near-term quantum computing devices. This project develops and experimentally tests a novel quantum algorithm for detecting specific leakage errors in qubit systems by harnessing entanglement, which are the strong correlations in quantum systems.

Thanks to these strong correlations, the algorithm allows an accurate detection of the leakage errors with substantially fewer experimental runs than required by state-of-the-art leakage detection protocols. Efficiently and precisely detecting specific information leakage errors is crucial for the current advancement of state-of-the-art quantum computing platforms, and in turn increases our ability to perform more precise quantum computing tasks with relevance throughout science and engineering.

The scientific goals of this project is to develop quantum algorithm for detecting potential leakage channels by using strongly-correlated (entangled) bipartite quantum systems. The correlations between the systems are specifically designed to probe and detect particular leakage error channels. The algorithm is suitable and has the flexibility to detect any leakage channel of concern; it is deterministic and allows one to detect the specific leakage channels with probability one.

The PIs and the student involved in this project are testing and benchmarking the algorithm on currently available quantum computing devices. The successful development and implementation of a leakage detection algorithm thus enhances our ability to suppress them, and in turn enhances the performance of currently available quantum computing platforms.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.