squidasm 0.9.0a2

NetSquid simulator for quantum networks running NetQASM applications

SquidASM

This is SquidASM, a simulator based on NetSquid that can execute applications written using NetQASM.

Installation

Prerequisites

SquidASM uses the NetSquid Python package. To install and use NetSquid, you need to first create an account for it. The username and password for this account are also needed to install squidasm.

From PyPI

SquidASM is available as a package on PyPI and can be installed with

pip install squidasm --extra-index-url=https://{netsquid-user-name}:{netsquid-password}@pypi.netsquid.org

From source

Make sure you have installed the latest netqasm version.

Also, the NETSQUIDPYPI_USER and NETSQUIDPYPI_PWD environment variables should be set to your user and password on the NetSquid forum, respectively.

Then run:

make install

to install SquidASM.

To verify the installation and run all tests and examples:

make verify

Simulator variants

SquidASM currently has 3 ways of simulating applications: multithread, singlethread and stack. Each of these can run applications written using the NetQASM SDK, but the way they must be written, and what kind of results they can give, is slightly different.

Multithread

Multithreaded simulation uses multiple threads: one thread for each application layer of each node, plus one thread for the NetSquid simulation of all quantum memories and links of all nodes combined.

Since application layer code is in a separate thread, it can do blocking operations, e.g. waiting for user input or receiving a message over TCP, without blocking the reset of the simulation. The way applications are written for the multithread simulator is hence closest to how they would be written when running on real hardware.

Since the quantum simulator (i.e. NetSquid) uses simulated time and does not work well with real-time interaction (like waiting for events outside the simulator process), the multithreaded simulator uses busy loops in some cases, which slows down overall execution.

Singlethread

Singlethreaded simulation uses a single thread that runs all application layer code of all nodes as well as all quantum simulation. All communication and classical events are also simulated in NetSquid, in contrast to the multithread simulator. This leads to faster simulation but poses some constraints to how applications are written.

The singlethread simulator is being deprecated in favor of the stack simulator.

Stack

The stack simulator is also singlethreaded, but does more accurate simulation of the components of the software stack that is intended to be run on physical quantum networks.

Usage

Multithread simulator

The multithread simulator is used as one of the backends of the netqasm package. See the netqasm package for more documentation on how to write NetQASM applications and run them using SquidASM.

Stack simulator

The main interface for the stack simulator is the run function in squidasm.run.stack.run. See examples/stack for examples of using the stack simulator.

Implementation

The code is divided into the following modules:

• nqasm: implementations of interfaces defined in the netqasm package
• run: code for setting up and starting simulations
• sim: internal simulation code
• util: various utility functions

License and patent

A patent application (NL 2029673) has been filed which covers parts of the software in this repository. We allow for non-commercial and academic use but if you want to explore a commercial market, please contact us for a license agreement.

Development

For code formatting, black and isort are used. Type hints should be added as much as possible.

Before code is pushed, make sure that the make lint command succeeds, which runs black, isort and flake8.

Contributors

In alphabetical order:

• Axel Dahlberg
• Bart van der Vecht (b.vandervecht[at]tudelft.nl)