Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Topological superconductivity in a van der Waals heterostructure   The designer approach has become a new paradigm in accessing novel quantum
phases of matter. Moreover, the realization of exotic states such as
topological insulators, superconductors and quantum spin liquids often poses
challenging or even contradictory demands for any single material. For example,
it is presently unclear if topological superconductivity, which has been
suggested as a key ingredient for topological quantum computing, exists at all
in any naturally occurring material . This problem can be circumvented by using
designer heterostructures combining different materials, where the desired
physics emerges from the engineered interactions between the different
components. Here, we employ the designer approach to demonstrate two major
breakthroughs - the fabrication of van der Waals (vdW) heterostructures
combining 2D ferromagnetism with superconductivity and the observation of 2D
topological superconductivity. We use molecular-beam epitaxy (MBE) to grow
two-dimensional islands of ferromagnetic chromium tribromide (CrBr$_3$) on
superconducting niobium diselenide (NbSe$_2$) and show the signatures of
one-dimensional Majorana edge modes using low-temperature scanning tunneling
microscopy (STM) and spectroscopy (STS). The fabricated two-dimensional vdW
heterostructure provides a high-quality controllable platform that can be
integrated in device structures harnessing topological superconductivity.
Finally, layered heterostructures can be readily accessed by a large variety of
external stimuli potentially allowing external control of 2D topological
superconductivity through electrical, mechanical, chemical, or optical means.

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The categories of this paper are: physics
7
The categories of this paper are: hep-th
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The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
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The categories of this paper are: stat
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The categories of this paper are: acc-phys
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The categories of this paper are: econ
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The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-lat
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The categories of this paper are: ao-sci
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The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: astro-ph