Abstract
Research in the field of low-temperature electronics is limited by the small
number of electrical contacts available on cryogenic set ups. This not only
restricts the number of devices that can be fabricated, but also the device and
circuit complexity. We present an on-chip multiplexing technique which
significantly increases the number of devices locally measurable on a single
chip, without the modification of existing fabrication or experimental set-ups.
We demonstrate the operation of the multiplexer by performing electrical
measurements of 256 quantum wires formed by split-gate devices using only 19
electrical contacts on a cryogenic set-up. The multiplexer allows the
measurement of many devices and enables us to perform statistical analyses of
various electrical features which exist in quantum wires. We use this
architecture to investigate spatial variations of electrical characteristics,
and reproducibility on two separate cooldowns. These statistical analyses are
necessary to study device yield and manufacturability, in order for such
devices to form the building blocks for the realisation of quantum integrated
circuits. The multiplexer provides a scalable architecture which makes a whole
series of further investigations into more complex devices possible.