Merge pull request #55 from qutech/update_references

Update references

README.md

@@ -3,6 +3,7 @@
 [![Build Status](https://travis-ci.org/qutech/filter_functions.svg?branch=master)](https://travis-ci.org/qutech/filter_functions)
 [![Documentation Status](https://readthedocs.org/projects/filter-functions/badge/?version=latest)](https://filter-functions.readthedocs.io/en/latest/?badge=latest)
 [![PyPI version](https://img.shields.io/pypi/v/filter-functions.svg)](https://pypi.org/project/filter-functions/)
+[![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.4575001.svg)](https://doi.org/10.5281/zenodo.4575001)
 
 ## Introduction
 Simply put, filter functions characterize a quantum system's susceptibility to noise at a given frequency during a control operation and can thus be used to gain insight into its decoherence. The formalism allows for efficient calculation of several quantities of interest such as average gate fidelity and even the entire quantum process up to a unitary rotation. Moreover, the filter function of a composite pulse can be easily derived from those of the constituent pulses, allowing for efficient assembly and characterization of pulse sequences.
@@ -74,7 +75,13 @@ Interactively using the documentation requires `jupyter`, and building a static
 ## Citing
 If this software has benefited your research, please consider citing:
 
-arXiv ID to be posted.
+T. Hangleiter, P. Cerfontaine, and H. Bluhm, “Filter function formalism and software package to compute quantum processes
+of gate sequences for classical non-markovian noise,” (2021), [arXiv:2103.02403](https://arxiv.org/abs/2103.02403)
+
+T. Hangleiter, I. N. M. Le, and J. D. Teske, “filter_functions: A package for efficient numerical calculation of generalized
+filter functions to describe the effect of noise on quantum gate operations,” (2021). [doi:10.5281/zenodo.4575001](http://doi.org/10.5281/zenodo.4575001)
+
+P. Cerfontaine, T. Hangleiter, and H. Bluhm, “Filter functions for quantum processes under correlated noise,” (2021), [arXiv:2103.02385](https://arxiv.org/abs/2103.02385).
 
 ## References
 [1]: Cywinski, L., Lutchyn, R. M., Nave, C. P., & Das Sarma, S. (2008). How to enhance dephasing time in superconducting qubits. Physical Review B - Condensed Matter and Materials Physics, 77(17), 1–11. [https://doi.org/10.1103/PhysRevB.77.174509](https://doi.org/10.1103/PhysRevB.77.174509)