Implementing quantum computing on superconducting qubits

Abstract

Quantum computing utilizes quantum mechanics to perform computations with superconducting qubits being the more mature technology as of writing in realizing a quantum computer. In this thesis, we describe an implementation of a Quantum Processor Unit (QPU), which is used to execute instructions in the form of microwave pulses on a superconducting qubit device through the use of signal generators and to perform qubit readout. We further extend the QPU as a platform to perform qubit characterization tasks such as spectroscopy and decoherence measurements in order to determine and optimize the working parameters to perform quantum gate operations. We also demonstrate the use of the QPU in performing qubit experiments such as Gauss Sum Factorization in determining the factors of an integer and the Bell Inequality test in examining the entanglement strength between a pair of qubits.

We bridge the divide of quantum computation and qubit hardware in the compilation of quantum circuits into microwave pulse sequences for the QPU to execute. The process of compilation, as well as hardware limitations and pre-compilation optimization procedures are discussed. Finally, we show an example of executing a variational quantum algorithm and break down this example in all layers from the quantum circuit provided by the user to the pulse sequence that will be executed on the QPU.