Theoretical And Experimental Studies Of Guiding For Cold Molecules With Charged Wires

Cold molecules provide broad application prospects, such as new platforms of quantum computing, precision measurement, lithography and cold chemistry and so on. Therefore, the research with cold molecules has become a new research field, and has developed rapidly in nearly a decade. Now there are a variety of methods to cool the chemical stabilization molecules into millikelvin. This thesis begins with an introduction to the principles, experiments and its latest progresses on the guiding and trapping of cold molecules, and the discussion on potential applications of cold molecules in the fields of physics and chemistry. Then, the electrostatic surface guiding with a single charged wire is studied in detail experimentally. Afterwards, an electrostatic surface guiding program using two charged wires has been proposed, studied in detail theoretically. Lastly, there is a summary of our work and the outlook of the future research.We realize the electrostatic surface guiding of cold molecules with single charged wire experimentally. We study the relation between the molecular beam and the temperature of pulse valve, the (2+1) REMPI spectra of ND3molecular in different source temperatures, the relationship between the guiding center position and the applied voltage, and the guiding efficiency. The results show that when the topper plate voltage is fixed, if the voltage of the wire increases, the guiding center increases. With the rise of the guiding center, the transverse temperature of guided molecules decreases. If the other conditions remain stable, the higher voltage of charged wire, the better guiding effect. When U1(U2)=17.3KV (20kV), the absolute efficiency can be achieved50%.We propose an electrostatic surface guiding program with two charged wires in theory. First, we introduce the theory of the Stark splitting for ND3and NH3molecules in an electric field. Second, we study the relationship between the spatial electric field distribution with the geometric dimensions (a, b, r) and the voltage of wires (U1.U2). We find that:guiding center is not only related to the geometry of the device but also related to the voltage of the wires. Therefore, it is more convenient to manipulate the molecules in this way. Finally, the efficiency of guiding is simulated by using the Monte Carlo simulation method.