Multicritical quantum sensors driven by symmetry-breaking

Understand

Quantum criticality has been demonstrated as a useful quantum resource for parameter estimation.

• This includes second-order, topological and localization transitions.
• In all these works reported so far, gap-to-gapless transition at criticality has been identified as a crucial resource for achieving the quantum-enhanced sensing, although there are several important concepts associated with criticality, such as long-range correlation, symmetry breaking.
• In this work, we show that symmetry-breaking alone can drive a quantum-enhanced sensing, even without any gap-to-gapless transition.