Conclusive quantum steering with superconducting transition-edge sensors

Area of Science:

• Quantum physics
• Quantum information science

Background:

• Quantum steering enables verification of entanglement between distant parties, even with untrusted measurement devices.
• Previous experimental tests of quantum steering relied on post-selection, leaving them vulnerable to 'detection loopholes' where untrusted devices could hide unfavorable data.

Purpose of the Study:

• To experimentally demonstrate quantum steering by closing the detection loophole.
• To achieve a violation of a steering inequality using a minimal number of measurement settings.

Main Methods:

• Utilized a highly efficient source of entangled photon pairs.
• Employed superconducting transition-edge sensors for photon detection.
• Combined these elements to achieve high conditional detection efficiency.

Main Results:

• Achieved a conditional detection efficiency of approximately 62% for entangled photons.
• Demonstrated a violation of a steering inequality by 48 standard deviations.
• Successfully closed the detection loophole in experimental tests of quantum steering.

Conclusions:

• The results provide a significant advancement in closing loopholes for quantum steering demonstrations.
• This work establishes a clear pathway towards practical applications of quantum steering.
• It also paves the way for future loophole-free Bell tests using photonic systems.