Quantum Computing: Fully-integrated Cryo-CMOS Spin-to-digital Readout for Spin Qubits
(19:38 + Q&A) Michele Castriotta, Politecnico di Milano -- Presentation from 2023 Workshop on Quantum Computing: Devices, Cryogenic Electronics and Packaging (QC-DCEP) ...
Summary: We have successfully fabricated and characterized a fully-integrated CMOS readout that operates at cryogenic temperatures for semiconductor spin qubits. Our readout achieves a comparable or even smaller single-shot readout time compared to RF-reflectometry. It is based on a direct spin-to-digital conversion, which includes a gated integrator for sensing the spin dependent current from a single-electron transistor and a programmable self-calibrated comparator to provide a digital output of the spin measurement. Our cryogenic comparator integrates CMOS-compatible floating-gate transistors as memory element to obtain a low-power and compact threshold, which is self-calibrated during an initialization phase to improve the detection accuracy. With our readout, we can resolve a variation of the sensing current of 250 pA with a sub-microsecond time resolution and a fidelity of 99.86%. What’s more, our readout consumes only 1.2 mW of power and occupies an area of less than 0.04 mm<sup>2</sup>.
Our solution doesn’t require off-chip components and the handling of microwave signals, which makes it more compact and reliable compared to the most common RF-reflectometry readout techniques. As a result, our approach exhibits promising scalability, particularly in scenarios where the co-integration of quantum processing units and readout electronics is feasible on a shared cryogenic board.
Michele Castriotta is a Ph.D student in Information Technology at the Department of Electronics, Information and Bioengineering (DEIB) of Politecnico di Milano, Italy. He received the M.Sc. (2020) Degrees in Electronics Engineering from Politecnico di Milano. His current research field is related to the development of very low noise instrumentation for high sensitivity electrical measurements at cryogenic temperature. He also investigates the aspects of the quantum transport in nano-scale devices.
Additional videos from the QC-DCEP Workhop can be accessed at https://attend.ieee.org/qc-dcep.
(19:38 + Q&A) Michele Castriotta, Politecnico di Milano -- Presentation from 2023 Workshop on Quantum Computing: Devices, Cryogenic Electronics and Packaging (QC-DCEP) ...
Summary: We have successfully fabricated and characterized a fully-integrated CMOS readout that operates at cryogenic temperatures for semiconductor spin qubits. Our readout achieves a comparable or even smaller single-shot readout time compared to RF-reflectometry. It is based on a direct spin-to-digital conversion, which includes a gated integrator ...