Quantum-coherence-free precision metrology by means of difference-signal amplification

Area of Science:

• Physics
• Metrology
• Quantum Mechanics

Background:

• Weak-value-amplification (WVA) leverages quantum interference for high-precision measurements.
• Joint WVA (JWVA) offers enhanced sensitivity but faces technical limitations like misalignment errors.

Purpose of the Study:

• To introduce and analyze a classical counterpart to JWVA, termed difference-signal amplification (DSA).
• To demonstrate that DSA can achieve signal amplification without relying on quantum coherence.
• To explore the practical implementation and optimal conditions for classical DSA.

Main Methods:

• Analysis of the difference-signal amplification (DSA) technique on classical mixed states.
• Derivation of a simplified expression for the amplified signal in DSA.
• Characterization of precision and identification of optimal working regimes for DSA.

Main Results:

• DSA achieves a significant amplification effect comparable to JWVA, but in a classical regime.
• A simple analytical expression for the amplified signal in DSA is derived.
• Optimal working conditions and precision characteristics for DSA are identified.

Conclusions:

• The classical DSA technique provides an alternative to JWVA with similar technical advantages.
• DSA may find practical applications in precision metrology by avoiding quantum coherence requirements.
• This work bridges quantum-inspired amplification techniques with classical measurement systems.