Exceptional point-enhanced piezoelectric thermometry via anti-parity-time symmetry

Temperature monitoring underpins critical processes in electronics, energy systems, and biomedical applications. Piezoelectric resonant temperature sensors based on lead zirconate titanate (PZT) are widely favored for their rapid thermal response and compact size, yet their linear temperature dependence severely limits the sensitivity. Here, we introduce a novel approach to piezoelectric thermometry by applying non-Hermitian physics and anti-parity-time (APT) symmetry to PZT resonators. The system couples two PZT resonators through energy interactions with gain/loss, forming an APT-symmetric architecture that operates at an exceptional point (EP). This configuration dramatically amplifies minute temperature-induced perturbations, achieving an ultrahigh temperature coefficient of frequency (TCF) of -1500 ppm·K^-1 indicating a 17-fold enhancement over conventional single PZT sensors (~88 ppm·K^-1), and over twice the sensitivity of state-of-the-art resonant temperature sensors without sacrificing power consumption or device size. Experimental results confirm a 2× improvement in signal-to-noise ratio (SNR) and dynamic adaptability. Unlike its PT-symmetric counterparts, APT symmetry tolerates intrinsic mismatches between PZTs, enabling robust EP operation and reconfigurability across a wide temperature range. By uniting non-Hermitian physics with piezoelectric platforms, this work establishes a new framework for piezoelectric thermometry in advanced electronics, energy storage, and biomedical systems.