Study On Single-Photon Transports In Microwave Superconducting Systems

Microwave quantum device,such as superconducting circuits,nanomechanical systems and artificial atomic systems,exhibits excellent performance due to the development of nanomanufacturing technology and quantum measurement and control technology.The development of the microwave quantum information technology is of great significance to understand the coupling of artificial atoms with feeder waveguides and the coupling of artificial atoms with microwave resonators.This paper is based on the theoretical study of microwave photon transport in real space.We propose a method for determining the quantization of a quarter-wavelength transmission line resonator,and pointed out the quantization effect of standing wave field in a quarter wavelength resonator is verified based on microwave traveling wave photon scattering measurement.Moreover,we demonstrate that the number of photons in the transmission line resonator can be detected nondestructively by IQ mixing technique through theoretical simulation.Our results indicate that the quarter-wavelength transmission line resonators are promising the quantum data bus to realize the coupling and information reading of solid-state qubits on chip.Different from the induced transparency of the original resonant absorbed light by regulating the optical properties of the medium with strong pump light,we propose an effective method to achieve the resonant total reflection of the microwave waveguide photons to the induced transmission transition.The results show that the total reflection of the resonant microwave can be transmitted by the original quarter wavelength resonator by introducing the coupling of the auxiliary quarter wavelength resonator.A quarter wavelength resonator sample corresponding to the above theoretical model was prepared by micro-nano machining technology.The microwave transmission characteristics of the sample were experimentally tested at extremely low temperature.The phenomena of electromagnetic induced transparency in the microwave band predicted by theory were observed,which confirmed the mode renormalization theory of the coupled resonator.As Nanomechanical resonator(NMR)plays an important role as a sensing probe in various high-precision detection,and the physical parameters of the NMR need to be calibrated.In this paper,we propose a method of embedding NMR in RF-Squid-based superconducting qubits is proposed to calibrate the physical parameters of NMR by means of transmission spectrum detecting transmitted microwaves.Theoretical calculations show that the vibration frequency and displacement parameters(both classical and quantum-mechanical)of the NMR can be estimated with high precision by the specific frequency points observed in the microwave transmission spectrum,i.e.,the fully transmitted and fully reflected points.The coplanar waveguide is indirectly coupled to NMR by superconducting qubits.This design is feasible with current technology and should facilitate the design of the required NMR for various precision measurement applications.Aiming at the problems of low detection efficiency and narrow detection frequency band of existing microwave single photon detectors,we propose a high efficiency detection method for traveling wave microwave photons.A two-atom coupling system is used as a detector,and the detectors are arranged around the microwave waveguide unevenly.By adjusting the coupling intensity between the two atoms and the photon,the high-efficiency detection of the single photon in broadband microwave can be realized.This design,using dc-SQUID to read out the system,indicate high-efficiency photon detection scheme is feasible in the existing experimental condition.