Scalability is a major challenge for large scale quantum computers, not only to design a large array of qubits, but moreover for the read-out of those qubits. Cryogenic electronics is a possible solution to overcome the huge temperature difference between qubit (at 20 mK) and electronics (at 300 K). This can lead to improved performance (shorter wires), less head injection (from 300 K) and an overall more integrated and smaller system.

To operate electronics at cryogenic temperatures (4 K), we characterized both CMOS and FPGAs running at those temperatures. Using those results, we opt to implement parts of the qubit read-out at low temperatures, such as analog-to-digital converters.

Harald Homulle received his bachelor (2012) and master degree (2014) from Delft University of Technology, both in the field of electrical engineering. During his master, he completed his internship at EPFL Lausanne developing a multi-channel Time to Digital Converter for fluorescence lifetime imaging.