Non-equilibrium criticality-enhanced quantum sensing with superconducting qubits.

Area of Science:

• Quantum physics
• Quantum sensing
• Condensed matter physics

Background:

• Quantum sensing offers precision beyond classical limits, known as quantum-enhanced precision.
• Quantum criticality and non-equilibrium dynamics are known resources for quantum-enhanced precision.
• Existing protocols often require complex preparation and measurements, limiting their applicability.

Purpose of the Study:

• To unify quantum criticality and non-equilibrium dynamics for enhanced quantum sensing.
• To explore a Stark-Wannier localization platform for quantum-enhanced sensitivity.
• To demonstrate a versatile platform for quantum sensing without stringent measurement requirements.

Main Methods:

• Implementation of a quantum probe on a 9-qubit superconducting quantum device.
• Utilizing a Stark-Wannier localization platform with a linear gradient field and particle tunneling.
• Exploring probe performance in extended, critical, and localized phases using computational-basis measurements.

Main Results:

• Achieved near-Heisenberg-limited precision by combining outcomes at distinct evolution times.
• Demonstrated enhanced sensitivity across an extended parameter regime by unifying quantum criticality and non-equilibrium dynamics.
• Showcased superior probe performance in the extended phase compared to the localized regime.

Conclusions:

• Stark-Wannier systems are versatile platforms for quantum sensing.
• The combination of criticality and non-equilibrium dynamics enhances precision over a wide parameter range.
• The developed approach offers high precision without stringent measurement requirements.