Intrinsic and induced quantum quenches for enhancing qubit-based quantum noise spectroscopy

Area of Science:

• Quantum Information Science
• Quantum Sensing
• Condensed Matter Physics

Background:

• Quantum sensing protocols often utilize probe qubit dephasing to study environments.
• These methods are crucial for applications like quantum processor noise mitigation and studying correlated electron states.

Purpose of the Study:

• To introduce a strategy for enhancing quantum sensing methods by exploiting inadvertent environmental quenches.
• To demonstrate how these quenches provide access to environmental response properties.

Main Methods:

• Analyzing the sensitivity of sensor qubit evolution to environmental quenches.
• Developing methods for direct measurement of bath temperature and non-thermal equilibrium states.
• Investigating deliberate control of quench physics for bath spectral function reconstruction.

Main Results:

• Environmental quenches, an effective sudden change in the Hamiltonian, are highly sensitive to the initial environmental state.
• These quenches enable direct measurement of bath temperature and detection of non-thermal equilibrium states.
• Controlled modulation of quench physics allows for reconstruction of the bath spectral function.

Conclusions:

• The proposed strategy enhances quantum sensing by leveraging environmental quenches.
• This approach offers new capabilities for characterizing quantum environments, including temperature and non-equilibrium states.
• The methods are applicable to diverse quantum sensing platforms like NV centers, quantum dots, and superconducting circuits.