Heralded Bell State of Dissipative Qubits Using Classical Light in a Waveguide.

Area of Science:

• Quantum Information Science
• Quantum Optics
• Condensed Matter Physics

Background:

• Maximally entangled two-qubit states, known as Bell states, are fundamental to quantum technologies.
• Open quantum systems typically suffer from dissipation, leading to decoherence and loss of quantum effects.

Purpose of the Study:

• To demonstrate the heralded generation of maximally entangled Bell states in intrinsically open qubits within a one-dimensional system.
• To investigate how continuous monitoring and driving can overcome dissipation to create quantum correlations.

Main Methods:

• Utilizing strong coherent driving and continuous monitoring in a one-dimensional system.
• Analyzing quantum jump trajectories and heralded events triggered by photon detection.
• Examining the system's steady state and its quantum correlations.

Main Results:

• Achieved heralded generation of a pure, maximally entangled Bell state in open qubits.
• Demonstrated that quantum correlations can be generated and maintained despite dissipation.
• Showed the Bell state survives strong coherent state input, which typically overwhelms quantum systems.

Conclusions:

• Continuous measurement and interference can generate entanglement in open systems, contrary to intuition.
• This method offers a simple approach to creating Bell states using classical light and photon detection.
• The technique, applied to qubits in a 1D continuum, could serve as a building block for quantum networks.