كامران صالحيان متي كلايي

The purpose of this research is to investigate and calculate the effect of excitation oscillator phase noise on quantum bits (qubits). First, we examine the difference between classical bits and quantum bits and introduce a sphere called the Bloch sphere on which quantum bits are mapped. Different quantum states are equivalent to rotating around this sphere. In the next part, we will discuss the concepts used and how different quantum gates work. Then we discuss how to realize and implement qubits, one of the suitable options for implementing qubits is to use microwave circuits and excitations at low temperatures. It can be shown that different quantum gates can be implemented using ideal microwave excitations. If noise from the environment is added to the system, it will cause the structure to not function properly. In this research, we first examine the effect of ambient noise and excitation phase noise on the qubit and show that these noises will cause unwanted rotation around the z axis and around the x and y axes. Then we calculate the effect of phase noise and provide a suitable criterion for eva‎luating phase noise for quantum computing. Then we perform calculations for two qubits that are coupled by a capacitor and redefine the introduced criterion for each qubit and show that the introduced criterion is the degree of similarity or correlation between the noise power spectrum of each of the qubits are dependent. Then we define the Allen deviation (two-sample variance) and calculate it and show how the Allen deviation and the power spectrum density of noises will change over time and what effect it has on quantum computations. At the end, we will have a summary of what was said and we will provide suggestions for improvement and continuation of the work.

كيوبيت , كره بلاخ , كيوبيت هاي ابررسانا , اثر نويز فاز بر روي كيوبيت , كنترل كيوبيت , انحراف آلن

Qubit , Bloch sphere , Superconducting qubits , The effect of phase noise on qubits , Qubit control , Allan deviation

Kamran Salehian

Dr. Majid Tayarani