Non-Hermitian Electromagnetics

In 1998, a famous proposal that the non-Hermitian Hamiltonians could also have real eigenspectra was put forward. Ever since then, the investigation of non-Hermitian physics has embraced rapid growth. Owing to the similarity between Maxwell's lightwave equation and Schrödinger equation under certain conditions, non-Hermitian systems were first developed in optical platforms. Our research has been focused on extending the notion of non-Hermitian systems to electronics and electromagnetics as they have infiltrated almost every aspect of our lives. We have developed the most typical non-Hermitian system that respects the parity-time (PT) symmetry by using electronic components. We have successfully observed the exotic spectral features possessed by the PT-symmetric systems in electromagnetic regimes. We have developed various theoretical frames of non-Hermitian electromagnetics facing the frontiers of applied physics, such as noise suppressing, sensitivity enhancement, and robust wireless power transfer. We have also proposed the potential to implement the non-Hermitian electromagnetic systems into real-life applications. 

 

Wearable & soft electronics for biomedical sensing

In the era of internet-of-things (IoTs), self-healthcare monitoring has become one of the vital parts of individuals' daily lives. Traditional sensors, actuators, and interrogation systems highly suffer from bulky and rigid materials which prevent them from being implemented in biomedical sensing, especially the epidermis and even implanted sensing scenarios. We are devoted to developing fully soft electronic and electromagnetic systems that can be directly attached to the human epidermis and even implanted in vivo. We have reached a significant milestone that a full soft and wearable smart mask was developed to wirelessly monitor the correctness of mask-wearing and cough frequency. We have also proposed a robust wireless interrogation platform to contactless and noninvasively acquire the pressure and temperature information within the skull. This innovative interrogation platform has indeed addressed the longstanding issue of near-field sensing that the misalignment between coil antennas may lead to inaccuracy of sensing. Additionally, our research also strives to look for appropriate composite materials with excellent mechanical properties with great electronic characteristics such as low dielectric loss and high conductivity. We are dedicating ourselves to developing the next-generation chipless, batteryless, and highly biocompatible wearable & soft electronics for biomedical sensing.

 

 

 

Secure communications & identifications

The 5th generation (5G) and 5G beyond technologies have given a rebirth of the IoTs. Tremendous intelligent devices such as smartphones, vehicles, and furniture interconnected to each other have imposed unneglectable threats to the information stolen and leakage. This information is highly susceptible to cyberattacks, especially those assisted by machine/deep learning algorithms. We have proposed to utilize the high entropy brought by the non-Hermitian spectral singularities to enlarge the low entropy that existed in electronic lumped elements. We have successfully implemented the divergent exceptional points (DEP) in to the wireless identification and secure communication scenarios, which can not only exhibit unclonability, unpredictability, and inreproducibility. We have also developed a random energy modulation via the optical singular points, coherent perfect absorber-laser (CPAL) points. The metastructure can manipulate the incident lightwaves in a highly random manner, from which the encryption keys can be extracted. Our papers published in Nature Communications and Science Advances have demonstrated our leading research in this area, where the quantum theory is implemented into real-life applications of secure communication and identification.