Information-theoretic approach to single-particle and two-particle interference in multipath interferometers

Area of Science:

• Quantum mechanics
• Quantum optics
• Quantum information science

Background:

• Interferometry is a key technique in quantum mechanics.
• Understanding particle interference is crucial for quantum technologies.
• Existing measures do not fully capture the interplay between single- and two-particle interference.

Purpose of the Study:

• To develop entropic measures for quantifying single-particle and two-particle interference.
• To investigate the trade-off relationship between these two types of interference.
• To establish the applicability of these measures to general quantum systems.

Main Methods:

• Formulation of entropic measures for interference strength.
• Analysis of multipath interferometers with entangled particle pairs.
• Derivation of an inequality governing the interference trade-off.
• Identification of specific two-particle states saturating the inequality.

Main Results:

• Proposed entropic measures quantify single- and two-particle interference.
• Demonstrated that optimal single-particle interference precludes two-particle interference, and vice versa.
• Derived a quantum mechanical inequality bounding the trade-off between interference types.
• Identified a class of two-particle states that reach this upper bound.

Conclusions:

• The developed entropic measures provide a robust framework for analyzing quantum interference.
• Quantum mechanics imposes fundamental limits on the simultaneous presence of single- and two-particle interference.
• The findings are applicable to a broad range of symmetric two-partite quantum systems.