SEU Professors Huang Qin'an and Dong Lei's Team Publishes Latest Breakthrough in Sensor Technology

Recently, the research team led by Prof. Huang Qing'an and Associate Prof. Dong Lei at the Key Laboratory of MEMS of the Ministry of Education, Southeast University, achieved breakthroughs in high-sensitivity and wide-dynamic-range inductance–capacitance (LC) sensors based on nonlinear parity–time (PT) symmetry. The work, entitled “A nonlinear parity–time-symmetric system for robust phase sensing” was published in Nature Electronics.

In quantum mechanics, the physical observablesare represented by operators. To ensure that observable quantities are real numbers, these operators are required to be Hermitian. However, in 1998, Bender et al. proposed that operators satisfying parity-time (PT) symmetry, even if non-Hermitian, can still exhibit real eigenvalues, leading to extensive and novel phenomena and applications in physics, optics, acoustics, electrical engineering, andrelated fields. Among these, the exceptional point (EP)-enhanced sensing realized in 2014 can significantly improve the sensitivity of sensors. However, this approach remains controversial because, at the exceptional point, eigenvalues coalesce and eigenvectors collapse, leading to simultaneous amplification of noise.

The EP-enhanced sensing scheme proposed in this workdemonstrates two key breakthroughs. First, nonlinear saturated gain is introduced to eliminate the imaginary parts of the frequency eigenvalues, effectively suppressing noise and significantly improving the signal-to-noise ratio. Second, the study proposes for the first time using the phase difference between gain–loss resonators as the sensing parameter. This phase exhibits a cube-root singularity, resulting in sensitivity that is an order of magnitude higher than that of conventional frequency-based sensing, while also offering a much wider dynamic range.

Using a nonlinear PT-symmetric LC temperature-sensing platform, the system can measure temperatures ranging from 36 °C to 55.5 °C, corresponding to asymmetric perturbations of 0%–3.95% applied to the PT-symmetric system. Experimental results demonstrate a normalized phase sensitivity exceeding 400, a dynamic range greater than 53.52 dB, and a signal-to-noise ratio of 63.8 dB. The phase noise measured at a 2 kHz offset from the center frequency is below –85 dBc/Hz. This research has resolved long-standing debates regarding the effectiveness of EP-based sensing and established a new paradigm for PT-symmetric phase-sensitive sensors. The proposed approach can be readily extended to sensing systems in physics, optics, acoustics, and related fields, highlighting its broad application potential.

Chen Dongyan, a PhD candidate from the School of Integrated Circuits, SEU, is thepaper's first author. Associate Prof. Dong Lei from the School of Electronic Science and Engineering and Prof. HuangQing'an from the School of Integrated Circuits are the co-corresponding authors. SEU is the sole contributing institution. This research was supported by the General Program of the National Natural Science Foundation of China (Grant No. 62274030) and the National Major Scientific Research Instrument Development Project of the National Natural Science Foundation of China (Grant No. 61727812).

Paper link:https://www.nature.com/articles/s41928-025-01542-8

Source: School of Integrated Circuits, SEU

Translated by: Melody Zhang

Proofread by: Gao Min

Edited by: Leah Li