【报告题目】：Multi-component catlike states in a thermal reservoir and fragility of their nonclassical features
【报告人】：Naeem Akhtar 博士，江苏大学物理系
【报告时间】：2024年6月5日，9:30-11:00，
【报告地点】：科技楼29-414
【报告摘要】： Compass states (4 component cat states) provide isotropic sub-Planck phase-space structure in the sense that the sensitivity to phase-space displacement is greater than that of shifting the vacuum state, making these nonclassical quantum states a potential resource for quantum metrology. In practical applications, noise from the environment can cause decoherence and alter the quantum nature of a state, making it challenging to retain nonclassical phase assets. This is a critical issue that has been studied for several types of quantum systems, and as a result, some beneficial strategies have been developed to protect the quantum properties of a quantum state against ambient decoherence. In our present work, we considered another type of compass states, which were recently obtained by adding (subtracting) to (from) superposed squeezed-states, and now we observed their intact with a thermal bath, and then by carefully analyzing the impact of decoherence on the quantum nature of our compasslike states, we found that decoherence aroused by this interaction have swiftly removed the miraculous phase-space features, and eventually our compasslike states are superseded into a thermal state. Our theoretical investigations revealed that increasing the average thermal photon number (temperature) of the reservoir, the squeezing parameter, or the number of added (or subtracted) photons to the squeezed-vacuum states accelerated the effects of decoherence on the nonclassical attributes. However, by decreasing the reservoir temperature to near-zero, we can preserve the nonclassical phasespace features of these states for a comparatively longer period. Furthermore, when compared to the photon-added illustration, our photon-subtracted compasslike state survived longer to maintain its nonclassical phase-space properties, making them a better choice for decoherence survival.
【参考文献】：https://doi.org/10.1103/PhysRevA.109.053718
