Utilizing quantum coherence in Cs Rydberg atoms for high-sensitivity room-temperature terahertz detection: a theoretical exploration

In recent years,terahertz (THz) technology has made significant progress in numerous applications;however,the highly sensitive,room-temperature THz detectors are still rare,which is one of the bottlenecks in THz research.In this paper,we proposed a room-temperature electrometry method for THz detection by laser spectroscopy of cesium(^(133)Cs) Rydberg atoms,and conducted a comprehensive investigation of the five-level system involving electromagnetically induced transparency (EIT),electromagnetically induced absorption (EIA),and Autler–Townes (AT) splitting in^(133)Cs cascades.By solving the Lindblad master equation,we found that the influence of the THz electric field,probe laser,dressing laser,and Rydberg laser on the ground state atomic population as well as the coherence between the ground state and the Rydberg state,plays a crucial role in the transformation and amplitude of the EIT and EIA signals.Temperature and the atomic vapor cell’s dimensions affect the number of^(133)Cs atoms involved in the detection,and ultimately determine the sensitivity.We predicted the proposed quantum coherence THz detection method has a remarkable sensitivity of as low as 10^(-9)V m^(-1)Hz^(-1/2).This research offers a valuable theoretical basis for implementing and optimizing quantum coherence effects based on Rydberg atoms for THz wave detection with high sensitivity and room-temperature operation.

Efficient Extractive Desulfurization of Fuel Oils Using N-Pyrrolidone/Alkylphosphate-Based Ionic Liquids

Four BrØsted acid ionic liquids(ILS)[MMP][DMP],[MEP][DEP],[HMP][DMP]and[HEP][DEP]were syn-thesized and used as extractants for desulfurization of aromatic sulfur compounds in model oil.The mutual solubil-ity of four ILs were investigated.The extraction equilibrium of four ILs could be reached in as soon as 5 min and the extraction capability followed the order[MMP][DMP]>[MEP][DEP]>[HEP][DEP]>[HMP][DMP].The S extraction showed the highest efficiency under the conditions of 30℃,30 min and 1∶1(V/V)IL∶oil.Under the optimal condition,70.9%of thiophene(TS),76.9%of benzothiophene(BT)and 87.5%of dibenzothiophene(DBT)in n-octane could be efficiently removed by[MMP][DMP].The multiple extraction and regeneration performance of[MMP][DMP]for TS was also investigated and the results were satisfying.These results suggest that[MMP][DMP]has the best extraction capability and can serve as a promising solvent for extractive desulfurization of fuel oils.