A Mechanical Oscillator Used To Be Coupled To A Superconducting Qubit

Compared with a classical computer,a quantum computer has great advantages.In many physical candidates being used to realize quantum computation,a superconducting quantum bit(qubit),which is a solid state system,is the most promising.The superconducting qubit is compatible with the traditional micro-fabrication process and can be combined with other variety of systems,such as microwave,optical and mechanical oscillators,to form a coupled quantum system.At the same time,a mechanical oscillator can be used to study the quantum mechanism and may have applications in the quantum computing.Due to its small mass,high quality factor and low loss,more and more attention has been paid to the mechanical oscillator and great achiements have been obtained.Here,to couple a superconducting qubit with a mechanical resonator,we have developed a fabrication process of the mechanical oscillator and measure its characteristics with the irradiation ofmicrowave and light.The main work of this thesis can be summarized as follows:1?We have developed a fabrication process of micro-mechanical oscillator based on a vacuum gap capacitor(VGC),in which a sacrificial layer is used to fabricate the suspended structure.Then we form superconducting resonance circuits with the VGC and a spiral inductor or a quarter wave resonator.2?In a dilution refrigerator with temepature below 20 mK,we use a microwave signal to drive the superconducting resonance circuit with VGC and a vector network analyzer to measure the transmission characteristic of S21 of the circuit.At the same time,we use a spectrum analyzer to measure the mechanical oscillator's sideband frequencies.3?We have designed an alignment set-up to assemble the device of VGC with optical irradiation,which includes back-up unit,movable optical fiber unit and the copper cavity to hold the device.Using a CCD platform and the designed alignment set-up,we assemble the device with optical fiber and successfully demonstrate the response of the mechanical oscillator to the laser.4?We have designed a coupled structure,in which a mechanical with VGC is coupled to a superconducting qubit and finished the fabrication of the samples.