  Quantum point contact or QPC -- a constriction in a semiconducting
two-dimensional (2D) electron system with a quantized conductance -- has been
found as the building block of novel spintronic, and topological electronic
circuits. They can also be used as readout electronic, charge sensor or switch
in quantum nanocircuits. A short and impurity-free constriction with
superconducting contacts is a Cooper pairs QPC analogue known as
superconducting quantum point contact (SQPC). The technological development of
such quantum devices has been prolonged due to the challenges of maintaining
their geometrical requirement and near-unity superconductor-semiconductor
interface transparency. Here, we develop advanced nanofabrication, material and
device engineering techniques and report on an innovative realisation of
nanoscale SQPC arrays with split gate technology in semiconducting 2D electron
systems, exploiting the special gate tunability of the quantum wells, and
report the first experimental observation of conductance quantization in hybrid
InGaAs-Nb SQPCs. We observe reproducible quantized conductance at zero magnetic
fields in multiple quantum nanodevices fabricated in a single chip and
systematically investigate the quantum transport of SQPCs at low and high
magnetic fields for their potential applications in quantum metrology, for
extremely accurate voltage standards, and fault-tolerant quantum technologies.

Quantum Physics;Mesoscale and Nanoscale Physics;Strongly Correlated Electrons;Superconductivity;Applied Physics