Adam Borkowski
supervisor: Witold Pleskacz
Silicon Quantum Computers use the principle of quantum mechanical phenomena such as superposition and entanglement to perform quantum operations based on wide spread and matured Silicon technologies. Like digital computers characterized by classical bits 1 and 0, quantum computers also process information through qubits. Critical parameter of such arrays of qubits is coherence time. They also need very fast pulse based classical control circuitry for the initialization , control and readout of their states. A low power D/A converter operating at or below 4.2K will serve this purpose.
In the current application, control is performed with discrete electronic system on the PCB. This causes a lot of issues. The main problem is large size of the PCB. Therefore, the system must be located outside the cryochamber and the signals must be led by wires. These conductors introduce a considerable capacity, which results in high power consumption of the DACs. Possible solution is to use dedicated integrated circuit, which can be placed inside the cryochamber. This allows to significantly reduce the number of external connections, which facilitates maintenance of low temperature inside the chamber. In addition, the loading capacitance of the transducer drops drastically, which gives opportunity to reduce the power consumption. Additionally, the benefit is a drastic reduction in thermal noise generated in the drivers DAC due to the fact that they operate at a very low temperature.