Paper review (#1131)

### Summary

Small paper edits.

### Details and comments

This PR addresses
#1124 and
#1129. We have

* included two new references 
* outlined the value proposition of Qiskit Experiments
* included a link to the experiment manuals.

---------

Co-authored-by: Helena Zhang <hadron.diaspora@gmail.com>

docs/paper/paper.bib

@@ -23,6 +23,20 @@ @article{Amico2023
   copyright = {arXiv.org perpetual, non-exclusive license}
 }
 
+@article{Ball2021,
+  doi = {10.1088/2058-9565/abdca6},
+  url = {https://dx.doi.org/10.1088/2058-9565/abdca6},
+  year = {2021},
+  month = {sep},
+  publisher = {IOP Publishing},
+  volume = {6},
+  number = {4},
+  pages = {044011},
+  author = {H. Ball and M. J. Biercuk and A. R. R. Carvalho and J. C. and M. Hush and L. A. De Castro and L. Li and P. J Liebermann and H. J. Slatyer and C. Edmunds and V. Frey and C. Hempel and A. Milne},
+  title = {Software tools for quantum control: improving quantum computer performance through noise and error suppression},
+  journal = {Quantum Sci. Technol.}
+}
+
 @article{Cross2019,
   title = {Validating quantum computers using randomized model circuits},
   author = {Cross, A. W. and Bishop, L. S. and Sheldon, S. and Nation, P. D. and Gambetta, J. M.},
@@ -123,6 +137,15 @@ @Article{Harris2020
   url = {https://doi.org/10.1038/s41586-020-2649-2}
 }
 
+@misc{Pasquale2023,
+  title = {Towards an open-source framework to perform quantum calibration and characterization},
+  author = {A. Pasquale and S. Efthymiou and S. Ramos-Calderer and J. Wilkens and I. Roth and S. Carrazza},
+  year = {2023},
+  eprint = {2303.10397},
+  archivePrefix = {arXiv},
+  primaryClass = {quant-ph}
+}
+
 @misc{Qiskit,
   author = {M. S. Anis and A. Mitchell and H. Abraham and A. Offei and R. Agarwal and G. Agliardi and M. Aharoni and I. Y. Akhalwaya and G. Aleksandrowicz and \emph{et al.}},
   title = {Qiskit: An Open-source Framework for Quantum Computing},

docs/paper/paper.md

@@ -85,14 +85,24 @@ Quantum development software packages such as Qiskit, ReCirq [@QuantumAI], tKet
 Forest [@Smith2016] are part of the quantum stack to execute quantum circuits on hardware.
 They also enable high-level applications that abstract away the quantum hardware. 
 Forest-benchmarking [@Forest] and pyGSTi [@pyGSTi] are tailored towards benchmarking of quantum hardware.
+Commercial solutions that provide quantum optimal control as a service now also exist [@Ball2021].
 However, there is still a need for open-source software that enables researchers and hardware 
 maintainers to easily execute characterization and calibration experiments.
-`Qiskit Experiments` is unique in this perspective as it provides low-level characterization 
-experiments that integrate with pulse-level control [@Alexander2020].
+Recently, software packages have started to emerge to fill this gap [@Pasquale2023]. 
+`Qiskit Experiments` is unique in this perspective as it provides open-source low-level 
+characterization experiments that integrate with pulse-level control [@Alexander2020].
+`Qiskit Experiments` greatly simplifies the execution of complex experiments and is 
+usable with any hardware exposed as a Qiskit backend.
+Indeed, a library provides many experiments which run multiple quantum circuits and complex fitting. 
+Crucially, each experiment only requires a few code lines to run with `Qiskit Experiments`.
+In addition, the base framework of `Qiskit Experiments` provides experimentalists a clear 
+interface to create new experiments. 
+They must (i) define how to construct the circuits, (ii) define the experiment options, 
+and optionally (iii) implement the analysis class, if not already present in the library.
 In addition, `Qiskit Experiments` provides a calibration framework to manage device calibration.
-This framework is usable with any hardware exposed as a Qiskit backend.
-For example, the `Qiskit Experiments` framework is used to explore measurements without qubit 
-reset [@Tornow2022], benchmarking [@Amico2023], characterize positive operator value measures [@Fischer2022], quantum 
+Experiments in the `Qiskit Experiments` library and custom extensions built on top of the 
+framework have been used to explore measurements without qubit reset [@Tornow2022], 
+benchmarking [@Amico2023], positive operator value measures [@Fischer2022], quantum 
 states [@Hamilton2022], and time-evolutions [@Greenaway2022], as well as calibrate gates [@Vazquez2022].
 
 ![
@@ -122,6 +132,8 @@ The shaded area is a $2\sigma$ confidence interval.
 # Documentation
 
 `Qiskit Experiments` documentation is available at [https://qiskit.org/documentation/experiments](https://qiskit.org/documentation/experiments).
+The documentation also includes [experiment manuals](https://qiskit.org/documentation/experiments/manuals) 
+that show how to run experiments such as the Quantum Volume presented above.
 
 # Acknowledgements