Quantum Limits of Superresolution in a Noisy Environment.

Area of Science:

• Quantum Optics
• Quantum Metrology
• Information Theory

Background:

• Super-resolution in quantum systems offers enhanced measurement precision.
• Quantum Fisher information quantifies the ultimate precision limit.
• Noise, such as thermal noise and dark counts, can degrade measurement performance.

Purpose of the Study:

• To analyze the ultimate quantum limit of resolving two identical sources in a noisy environment.
• To investigate the impact of noise-induced false excitations on resolution.
• To quantitatively assess the resolution limit for identical thermal sources.

Main Methods:

• Theoretical analysis of quantum Fisher information for arbitrary quantum states.
• Investigation of classical Fisher information under false excitation.
• Quantitative analysis using finite spatial mode multiplexing for thermal sources.

Main Results:

• Quantum Fisher information converges to zero as source separation approaches zero in noisy environments.
• False excitations (e.g., thermal noise, dark counts) universally limit resolution.
• Noise amount directly correlates with the resolution limit in practical systems.

Conclusions:

• Super-resolution is fundamentally limited by noise-induced false excitations.
• Quantum and classical Fisher information approach zero in the presence of noise, hindering resolution.
• Noise mitigation strategies are crucial for achieving high-resolution quantum measurements.