README.md

Quantum Circuits Compiler with Staging

This repository contains various experimental quantum circuit evaluators and compilers. They take a Toffoli-Hadamard quantum circuit as input, and simulates the probability amplitudes of all possible outcomes.

• The directory src/main/scala/feynman contains various Feynman-style simulators implemented using continuations.

  • QContSim1.scala contains a pure implementation and uses delimited continuations shift/reset (following the Quantum Continuation paper).
  • QContSim2.scala implements an evaluator written in CPS and uses side-effect to perform path summarization.
  • QCompilerCPS.scala is a staged CPS evaluator (written with Lightweight Modular Staging) that can generate C code for simulation.

• The directory src/main/scala/schrodinger contains various Schrodinger-style simulators implemented with linear algebra computation.

  • Schrodinger.scala is an unstaged implementation.
  • StagedSchrodinger.scala is a staged implementation that specializes over static gate matrices.

Example

To see an example of the compiler in action, run the following command in sbt:

sbt:quantum-lms-compiler> runMain quantum.feynman.staged.TestQC

This will take the circuit for the Simon problem as input and execute the generated C program snippet.cpp. The C program is compiled with g++ -std=c++20 -O3. Running the generated program prints all states and their probability amplitudes:

0.5|0000⟩
0.5|0011⟩
0.5|1100⟩
-0.5|1111⟩