Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: PennyLane: Automatic differentiation of hybrid quantum-classical
  computations   PennyLane is a Python 3 software framework for optimization and machine
learning of quantum and hybrid quantum-classical computations. The library
provides a unified architecture for near-term quantum computing devices,
supporting both qubit and continuous-variable paradigms. PennyLane's core
feature is the ability to compute gradients of variational quantum circuits in
a way that is compatible with classical techniques such as backpropagation.
PennyLane thus extends the automatic differentiation algorithms common in
optimization and machine learning to include quantum and hybrid computations. A
plugin system makes the framework compatible with any gate-based quantum
simulator or hardware. We provide plugins for Strawberry Fields, Rigetti
Forest, Qiskit, Cirq, and ProjectQ, allowing PennyLane optimizations to be run
on publicly accessible quantum devices provided by Rigetti and IBM Q. On the
classical front, PennyLane interfaces with accelerated machine learning
libraries such as TensorFlow, PyTorch, and autograd. PennyLane can be used for
the optimization of variational quantum eigensolvers, quantum approximate
optimization, quantum machine learning models, and many other applications.

16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
6
The categories of this paper are: astro-ph
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th