Detecting initial correlations via correlated spectroscopy in hybrid quantum systems.

Area of Science:

• Quantum physics
• Mesoscopic quantum systems
• Quantum information science

Background:

• Mesoscopic quantum systems interact with their environment, leading to correlations that influence physical properties.
• Existing experimental methods for characterizing these systems often neglect initial correlations or scale poorly with system size.

Purpose of the Study:

• To develop a novel experimental technique for characterizing system-environment correlations.
• To create a method that is agnostic to initial correlations and scalable.
• To demonstrate the technique's applicability to Nitrogen Vacancy (NV) centers.

Main Methods:

• A new technique is presented that is independent of system-environment correlations.
• The method is applied under specific experimental constraints to detect and measure correlations.
• The technique is tested on two distinct NV-center-based quantum systems.

Main Results:

• The technique successfully detected dark spins in an NV center coupled to a P1 defect.
• It quantified interaction strength and the effective number of interacting NV centers in a hybrid quantum system (NV coupled to an optical cavity).
• The method demonstrated the ability to extract information from initial correlations.

Conclusions:

• The developed technique offers a robust way to characterize quantum systems and their environmental interactions.
• It overcomes limitations of existing methods by handling initial correlations.
• The successful application to NV centers highlights its potential for advancing quantum sensing and quantum information processing.