Recently, the Quantum Theory and Functional Devices Research Group of our institute has published a paper entitled "High-Performance Infrared Self-Powered Photodetector Based on 2D van der Waals Heterostructures" in the internationally renowned academic journal Advanced Functional Materials. This paper proposes a high-performance self-powered infrared photodetector based on PdSe₂/MoTe₂ van der Waals heterostructures. Operating at zero bias, the device achieves an ultra-broad spectral response ranging from 300 nm to 4050 nm, with performance metrics at 980 nm comparable to those of 2D/3D heterostructure devices. Furthermore, it reveals three essential conditions for constructing high-performance 2D/2D infrared self-powered photodetectors: a large work function difference between the two materials, high infrared absorption, and type-II band alignment. Unlike existing 2D/3D photodetectors operating in the infrared region, this detector provides a new design concept for miniaturized, low-power-consumption 2D/2D infrared photodetectors, and holds enormous application potential in fields such as infrared imaging technology, flexible electronics, and the design of Internet of Things (IoT) devices.
In addition, the research group has published a paper entitled "Enhancement in the temperature sensing of a reservoir by a Kerr-nonlinear resonator" in the internationally renowned academic journal Physical Review A. This paper proposes a technical scheme for accurately measuring the temperature of a quantum reservoir using a Kerr-nonlinear resonator. Thermalization in the scheme is evaluated through fidelity, and the metrological potential of the quantum thermometer scheme is assessed using quantum Fisher information. The temperature precision can be significantly improved by increasing the Kerr nonlinear coefficient and the driving amplitude. Furthermore, the underlying physical mechanisms are explored by analyzing the probe purity in the steady state and evaluating the performance of homodyne and heterodyne detection methods. Studies have shown that optimal homodyne detection is always superior to heterodyne detection.
The research group has also explored the influence of photon addition and subtraction operations on the nonclassical effects of superposed deformed kitten states in phase space. Through two operational orders (addition followed by subtraction, and subtraction followed by addition), multiphoton operations can generate nearly isotropic sub-shot-noise structures, whose properties are affected by the operational order: photon addition compresses the structure, while photon subtraction either expands it or renders it ineffective. Optimal multiphoton operations can enhance structural isotropy and significantly improve the state's sensitivity to displacement, surpassing the standard quantum limit. This discovery provides a new tool for quantum metrology and precision measurement, and holds promising applications in quantum sensing, imaging, and information processing. The research results have been published in Physical Review A under the title "Sub-shot-noise sensitivity via superpositions of two deformed kitten states".
