Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantised Charge Transport driven by a Surface Acoustic Wave in induced
  unipolar and bipolar junctions   Surface acoustic waves (SAWs) have been used to transport single electrons
across long distances of several hundreds of microns. They can potentially be
instrumental in the implementation of scalable quantum processors and quantum
repeaters, by facilitating interaction between distant qubits. While most of
the work thus far has focused on SAW devices in doped GaAs/AlGaAs
heterostructures, we have developed a method of creating lateral p-n junctions
in an undoped heterostructure containing a quantum well, with the expected
advantages of having reduced charge noise and increased spin-coherence
lifetimes due to the lack of dopant scattering centres. We present experimental
observations of SAW-driven single-electron quantised current in an undoped
GaAs/AlGaAs heterostructure, where single electrons were transported between
regions of induced electrons. We also demonstrate pumping of electrons by a SAW
across the sub-micron depleted channel between regions of electrons and holes,
and observe light emission at such a lateral p-n junction. Improving the
lateral confinement in the junction should make it possible to produce a
quantised electron-to-hole current and hence SAW-driven emission of single
photons.

9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
12
The categories of this paper are: nucl-th
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The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
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The categories of this paper are: solv-int
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The categories of this paper are: eess
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The categories of this paper are: astro-ph