Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Germanium quantum well Josephson field effect transistors and
  interferometers   Hybrid superconductor-semiconductor structures attract increasing attention
owing to a variety of potential applications in quantum computing devices. They
can serve to the realization of topological superconducting systems, as well as
gate-tunable superconducting quantum bits. Here we combine a SiGe/Ge/SiGe
quantum-well heterostructure hosting high-mobility two-dimensional holes and
aluminum superconducting leads to realize prototypical hybrid devices, such as
Josephson field-effect transistors (JoFETs) and superconducting quantum
interference devices (SQUIDs). We observe gate-controlled supercurrent
transport with Ge channels as long as one micrometer and estimate the induced
superconducting gap from tunnel spectroscopy measurements in superconducting
point-contact devices. Transmission electron microscopy reveals the diffusion
of Ge into the aluminum contacts, whereas no aluminum is detected in the Ge
channel.

30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex