Optimal Allocation of Pauli Measurements for Low-Rank Quantum State Tomography

Abstract: The process of reconstructing quantum states from experimental measurements, accomplished through quantum state tomography (QST), plays a crucial role in verifying and benchmarking quantum devices. A key challenge of QST is to find out how the accuracy of the reconstruction depends on the number of state copies used in the measurements. When multiple measurement […]

Erasure-Tolerance Scheme for the Surface Codes on Neutral Atom Quantum Computers

Abstract: Neutral atom arrays manipulated with optical tweezers are promising candidates for fault-tolerant quantum computers due to their advantageous properties, such as scalability, long coherence times, and optical accessibility for communication. A significant challenge to overcome is the presence of non-Pauli errors, specifically erasure errors and leakage errors. Previous work has shown that leakage errors […]

Quantum Detection Over Quantum Channels With Uncertainty

Abstract: In quantum state discrimination, the design of measurement operators and probe states is typically formulated under the assumption that the set of possible states is perfectly known, but this may yield designs that are sensitive to deviations in the realized set of states. For example, the channel through which a transmitted state is sent […]

Benchmarking the Ability of a Controller to Execute Quantum Error Corrected Non-Clifford Circuits

Abstract: Reaching fault-tolerant quantum computation relies on the successful implementation of non-Clifford circuits with quantum error correction (QEC). In QEC, quantum gates and measurements encode quantum information into an error-protected Hilbert space, while classical processing decodes the measurements into logical errors. QEC non-Clifford gates pose the greatest computation challenge from the classical controller’s perspective, as […]

Reducing Quantum Error Correction Overhead With Versatile Flag-Sharing Syndrome Extraction Circuits

Abstract: Given that quantum error correction processes are unreliable, an efficient error syndrome extraction circuit should use fewer ancillary qubits, quantum gates, and measurements while maintaining low circuit depth, to minimize the circuit area, roughly defined as the product of circuit depth and the number of physical qubits. We propose to design parallel flagged syndrome […]

Decoding Quantum Error Correction Codes With Local Variation

In this article, we investigate the role of local information in the decoding of the repetition and surface error correction codes for the protection of quantum states. Our key result is an improvement in resource efficiency when local information is taken into account during the decoding process: the code distance associated with a given logical […]