Fast cryogenic probing of quantum dot spin qubit devices

Fast feedback from cryogenic electrical characterization measurements is key for the successful development of scalable quantum computing technology. At room temperature, high-throughput device testing is accomplished with a probe-based solution, where electrical probes are repeatedly positioned onto devices for acquiring statistical data. In this work, we present a probe station that can be operated from room temperature down to 1.4 K [de Kruijf et al., Rev. Sci. Instrum. 94, 054707 (2023)]. It is designed for 2x2 cm² chips, that are moved with respect to a multi-contact probe card using closed-loop piezo-based positioners. This prober is compact enough to fit inside a standard cryogenic magnet system and is compatible with both direct-current and radio-frequency signals, thereby making it a versatile tool perfectly suited for gathering statistical data on qubits. A large variety of electronic devices can be tested. We showcase the performance of the prober by characterizing silicon fin field-effect transistors as a host for quantum dot spin qubits [Camenzind and Geyer et al., Nat. Electron. 5, 178 (2022)]. Such a tool can massively accelerate the design-fabrication-measurement cycle and provide important feedback for process optimization toward building scalable quantum circuits.



Supported by the NCCR SPIN, Swiss NSF, and the Georg H. Endress Foundation.