This paper explores the use of boundary time crystals (BTCs) in quantum metrology to enhance the precision of parameter estimation. The authors demonstrate that the transition from a symmetry-unbroken phase to a BTC phase, characterized by a second-order transition, exhibits quantum-enhanced sensitivity quantified by quantum Fisher information (QFI). They determine the critical exponents of the system and show that a simple measurement can achieve this enhanced precision, highlighting the potential of harnessing decoherence for quantum-enhanced sensing.

Victor Montenegro, Marco G. Genoni, Abolfazl Bayat, Matteo G. A. Paris