Experimental display of generalized wave-particle duality

Area of Science:

• Quantum mechanics
• Quantum optics

Background:

• Wave-particle duality (WPD) is a fundamental concept in quantum mechanics.
• Quantifying WPD traditionally involves measurable features like fringe visibility (V) and path distinguishability (D).
• Existing constraints, such as V² + D² ≤ 1, apply to physical objects exhibiting WPD, termed 'quantons'.

Purpose of the Study:

• To derive and experimentally test generalized constraints on WPD.
• To explore the role of internal degrees of freedom (DOF) of quantons as path markers.
• To investigate how V and D relate to other quantifiers and reveal hidden coherences.

Main Methods:

• Theoretical derivation of generalized WPD constraints involving internal DOF.
• Experimental testing of two-qubit constraints using linear optics setups with optical light beams.
• Measurement of fringe visibility (V) and path distinguishability (D).

Main Results:

• Experimental results show excellent agreement with theoretical predictions for the tested generalized constraints.
• The study successfully tested constraints derived from simultaneously engaging a quanton and its internal DOF.
• Hidden coherences in both quantum and classical light were revealed through generalized quantifiers.

Conclusions:

• The derived generalized constraints provide a more comprehensive understanding of WPD.
• Linear optics setups are suitable for experimentally testing these generalized WPD constraints.
• Quantifiers like V and D are valuable for both quantifying and generalizing the concept of WPD.