Proposed Robust Entanglement-Based Magnetic Field Sensor Beyond the Standard Quantum Limit

Area of Science:

• Quantum physics
• Quantum metrology
• Quantum sensing

Background:

• Entanglement-based quantum metrology shows promise but is limited by fragile entangled states susceptible to experimental imperfections.
• Achieving quantum sensing beyond the standard quantum limit in realistic systems remains a challenge due to decoherence.

Purpose of the Study:

• To demonstrate a method for magnetic field sensing that overcomes limitations imposed by decoherence and experimental imperfections.
• To achieve sensing accuracy beyond the standard quantum limit using realistic entangled states.

Main Methods:

• Utilized a realistic entangled state, manufacturable with current technology.
• Investigated the performance of the entangled state under decoherence effects.
• Quantified the magnetic field sensing accuracy achieved by the proposed scheme.

Main Results:

• The proposed scheme successfully senses magnetic fields with accuracy exceeding the standard quantum limit.
• The method remains effective even in the presence of decoherence.
• The required entangled states are realistic and can be created using current technology.

Conclusions:

• It is possible to achieve practical quantum sensing beyond the standard quantum limit, even under decoherence.
• The developed scheme offers a viable pathway for realizing practical entanglement-based magnetic field sensors.
• This work could significantly advance the field of quantum sensing technology.