nquesada/realistic-quantum-states

This repository contains the source code used to produce the results presented in the paper "Simulating realistic non-Gaussian state preparation".

Simulating realistic quantum states

Simulating non-Gaussian quantum state preparation with loss via the fastest known classical method to calculate loop hafnians.

This repository contains the source code used to produce the results presented in "Simulating realistic non-Gaussian state preparation" arXiv:1905.07011.

Contents

The included script cubic_phase.py uses the loop hafnian algorithm to explore the loss parameter space of a heralded weak cubic phase state, as given in arXiv:1809.04680. The script generates contour plots of the resulting fidelity, Wigner Log Negativity, and probability as a function of heralding and heralded loss.

Requirements

To perform the quantum state preparation and parameter search, the script uses the Gaussian backend of Strawberry Fields. In addition, the hafnian library is required for efficient computation of loop hafnians, and matplotlib for graph generation.

Due to subsequent interface upgrades, the scripts in this repository work only with Strawberry Fields version <= 0.10.0 and Hafnian version <=0.1.2.

All of these prerequisites can be installed via pip:

pip install strawberryfields==0.10 hafnian=0.1.2 matplotlib

Authors

Nicolás Quesada, Luke Helt, Josh Izaac, Juan Miguel Arrazola, Rahaneh Shahrokhshahi, Casey Myers, and Krishna Kumar Sabapathy.

If you are doing any research using this source code, the Hafnian library, and Strawberry Fields, please cite the following three papers:

Nicolás Quesada, Luke Helt, Josh Izaac, Juan Miguel Arrazola, Rahaneh Shahrokhshahi, Casey Myers, and Krishna Kumar Sabapathy. "Simulating realistic non-Gaussian state preparation", arXiv, 2019. arXiv:1905.07011

Andreas Björklund, Brajesh Gupt, and Nicolás Quesada. "A faster hafnian formula for complex matrices and its benchmarking on the Titan supercomputer", Journal of Experimental Algorithmics (JEA) 24.1 (2019): 11.

Nathan Killoran, Josh Izaac, Nicolás Quesada, Ville Bergholm, Matthew Amy, and Christian Weedbrook. "Strawberry Fields: A Software Platform for Photonic Quantum Computing", Quantum, 3, 129 (2019).

License

This source code is free and open source, released under the Apache License, Version 2.0.