Minimal Entanglement Witness from Electrical Current Correlations

Area of Science:

• Quantum physics
• Condensed matter physics
• Quantum information science

Background:

• Demonstrating entanglement in mobile electrons within solid-state conductors remains a significant challenge.
• Existing methods often lack unambiguous verification or require complex setups.

Purpose of the Study:

• To theoretically investigate a generic setup for entangling and detecting mobile electrons.
• To propose a practical method for unambiguously verifying electron entanglement in conductors.

Main Methods:

• Theoretical analysis of a generic entangler-detector setup.
• Utilizing current cross-correlation measurements for entanglement witnessing.
• Considering non-zero detector efficiencies and non-collinear polarization vectors.

Main Results:

• A witness for entanglement between two flying electron qubits can be constructed from only two current cross-correlation measurements.
• All entangled pure states and most mixed states are detectable with two measurements.
• Maximally entangled states require three measurements for detection.

Conclusions:

• The proposed method offers a feasible approach for unambiguous entanglement detection of mobile electrons.
• This work provides optimal detector settings for entanglement witnessing, advancing quantum technologies.