Distributed quantum sensing with measurement-after-interaction strategies

Area of Science:

• Quantum Information Science
• Quantum Metrology
• Quantum Sensing

Background:

• Multiparameter quantum estimation is crucial for precision measurements.
• Standard linear measurements face limitations, especially with non-Gaussian states.
• Measurement-after-interaction (MAI) strategies offer a potential improvement.

Purpose of the Study:

• To investigate MAI strategies for multiparameter quantum estimation.
• To analyze the impact of local vs. nonlocal additional evolution in MAI.
• To benchmark MAI performance in discrete- and continuous-variable systems.

Main Methods:

• Benchmarking MAI strategies in discrete- and continuous-variable quantum systems.
• Analyzing probe state evolution before linear measurements.
• Deriving analytical results for multiparameter squeezing and scaling laws.

Main Results:

• MAI strategies significantly enhance multiparameter sensitivity and robustness against noise.
• Nonlocal evolution in MAI provides distinct advantages.
• MAI protocols achieve Heisenberg scaling for spin-squeezed states, especially with non-Gaussian states.
• Standard linear measurements are insufficient for certain non-Gaussian states.

Conclusions:

• MAI strategies offer a powerful approach to overcome limitations in multiparameter quantum estimation.
• These protocols demonstrate superior performance, particularly in noisy environments and with complex quantum states.
• The findings are applicable to current experimental platforms like atomic ensembles and optical fields.