Cryogenic Embedded System to Support Quantum Computing: From 5nm FinFET
to Full Processor
Abstract
Quantum computing can enable novel algorithms infeasible for classical
computers. For example, new material synthesis and drug optimization
could benefit if quantum computers offered more quantum bits (qubits).
One obstacle for scaling up quantum computers is the connection between
their cryogenic qubits at a few (milli)kelvin and the traditional
processing system on chip (SoC) at room temperature ( 300 K). Through
this connection, outside heat leaks to the qubits and can disrupt their
state. Hence, moving the SoC into the cryogenic part eliminates this
heat leakage. However, the cooling capacity is limited, requiring a
low-power SoC, which, at the same time, has to classify qubit
measurements under a tight time constraint. In this work, we explore for
the first time if an off-the-shelf SoC is a plausible option for such a
task. Our analysis starts with measurements of state-of-the-art 5 nm
FinFETs at 10 K and 300 K. Then, we calibrate a transistor compact model
and create two standard cell libraries, one for each temperature. We
perform synthesis and physical layout of a RISC-V SoC at 300 K and
analyze its performance at 10 K. Our simulations show that the SoC at 10
K is plausible but lacks the performance to process more than a few
thousand qubits under the time constraint.