Mixed state discrimination using optimal control

Abstract

We present theory and experiment for the task of discriminating two nonorthogonal states, given multiple copies. We implement several local measurement schemes, on both pure states and states mixed by depolarizing noise. We find that schemes which are optimal (or have optimal scaling) without noise perform worse with noise than simply repeating the optimal single-copy measurement. Applying optimal control theory, we derive the globally optimal local measurement strategy, which outperforms all other local schemes, and experimentally implement it for various levels of noise.

Corrected ref 1 date; 4 pages & 4 figures + 2 pages & 3 figures supplementary material

References in corpus (5)

• Entanglement-free Heisenberg-limited phase estimation
• Quantum Kalman Filtering and the Heisenberg Limit in Atomic Magnetometry
• The quantum Chernoff bound as a measure of distinguishability between density matrices: application to qubit and Gaussian states
• Demonstration of near-Optimal Discrimination of Optical Coherent States
• Quantum Control of a Single Qubit

Cited by in corpus (22)

• Quantum feedback: theory, experiments, and applications
• Optimum mixed-state discrimination for noisy entanglement-enhanced sensing
• Experimental feedback control of quantum systems using weak measurements
• Recursively Adaptive Quantum State Tomography: Theory and Two-qubit Experiment
• Local discrimination of mixed states
• Characterization of a qubit Hamiltonian using adaptive measurements in a fixed basis
• Feedback control in quantum optics: an overview of experimental breakthroughs and areas of application
• Realizable receivers for discriminating arbitrary coherent-state waveforms and multi-copy quantum states near the quantum limit
• Multiple-copy state discrimination: Thinking globally, acting locally
• Determination of maximal Gaussian entanglement achievable by feedback-controlled dynamics
• Null Values and Quantum State Discrimination
• Quantum State Discrimination Using the Minimum Average Number of Copies
• Optimized mitigation of random-telegraph-noise dephasing by spectator-qubit sensing and control
• Minimum-error discrimination of entangled quantum states
• Discriminating mixed qubit states with collective measurements
• Experimental quantum state discrimination using the optimal fixed rate of inconclusive outcomes strategy
• Beating the Classical Limits of Information Transmission using a Quantum Decoder
• Local unambiguous discrimination of symmetric ternary states
• Enforcing dissipative entanglement by feedback
• Multiple-copy state discrimination of noisy qubits
• Attainability of quantum state discrimination bounds with collective measurements on finite copies
• Quantum hypothesis testing via robust quantum control