Qadence 2 Platforms

!!! note Qadence 2 Platforms is currently a work in progress and is under active development.

Please be aware that the software is in an early stage, and frequent updates, including breaking changes, are to be expected. This means that:
* Features and functionalities may change without prior notice.
* The codebase is still evolving, and parts of the software may not function as intended.
* Documentation and user guides may be incomplete or subject to significant changes.

Qadence 2 Platforms is a collection of functionalities that transforms Qadence IR into backend-specific data and constructors, to be executed by backend methods. It is not intended to be used directly by Qadence 2 users, but rather those who need to implement or extend backends, quantum instruction primitives, compiler or backend directives, etc.

Installation

!!! note it is advised to set up a python environment before installing the package.

To install the current version, there is currently one option:

Installation from Source

Clone this repository by typing on the terminal

git clone https://github.com/pasqal-io/qadence2-platforms.git

Go to qadence2-platforms folder and install it using hatch:

python -m pip install hatch

and run hatch to create or reuse the project environment:

hatch -v shell

Description

Platforms

This package should not be used directly by the user. It is used to convert Qadence IR into backend-compatible data, and to execute it with extra options (provided by the compilation process, either on Qadence 2 expressions or Qadence 2 core).

Qadence 2 Intermediate Representation (IR)

Qadence 2 expressions is being compiled into an IR comprised of both quantum and classical operations.

Platforms API

The backend module exposes a single compile_to_backend function which accepts a Model and a string denoting the backend.

Platforms Backend

Each submodule under backend is expected (1) to translate the IR data into backend-compatible data, (2) to provide instruction conversions from IR to backend, (3) to handle the storage and embedding of parameters, and (4) to implement execution process for run, sample and expectation.

Usage

Example

from qadence2_ir.types import (
    Model,
    Alloc,
    AllocQubits,
    Call,
    Assign,
    QuInstruct,
    Support,
    Load
)


Model(
    register = AllocQubits(
        num_qubits = 3,
        qubit_positions = [(-2,1), (0,1), (1,3)],
        grid_type = "triangular",
        grid_scale = 1.0,
        options = {"initial_state": "010"}
    ),
    inputs = {
        "x": Alloc(1, trainable=False),
        "t": Alloc(1, trainable=False),      # time
        "Omega": Alloc(4, trainable=True),   # 4-points amp. modulation
        "delta": Alloc(1, trainable=False), # detuning
    },
    instructions = [
        # -- Feature map
        Assign("%0", Call("mul", 1.57, Load("x"))),
        Assign("%1", Call("sin", Load("%0"))),
        QuInstruct("rx", Support(target=(0,)), Load("%1")),
        # --
        QuInstruct("h", Support.target_all()),
        QuInstruct("not", Support(target=(1,), control=(0,))),
        QuInstruct(
		        "qubit_dyn",
		        Support(control=(0,), target=(2,)),
		        Load("t"),
		        Load("Omega"),
		        Load("delta"),
		    )
    ],
    directives = {"digital-analog": True},
)

Compiling a pyqtorch circuit and computing gradients using torch.autograd

import torch
import pyqtorch as pyq
from qadence2_ir.types import (
    Model, Alloc, AllocQubits, Load, Call, Support, QuInstruct, Assign
)

from qadence2_platforms.compiler import compile_to_backend


model = Model(
    register=AllocQubits(num_qubits=2),
    inputs={
        "x": Alloc(size=1, trainable=False),
    },
    instructions=[
        Assign("%0", Call("mul", 1.57, Load("x"))),
        Assign("%1", Call("sin", Load("%0"))),
        QuInstruct("rx", Support(target=(0,)), Load("%1")),
        QuInstruct("not", Support(target=(1,), control=(0,))),
    ],
    directives={"digital": True},
)
api = compile_to_backend(model, "pyqtorch")
f_params = {"x": torch.rand(1, requires_grad=True)}
wf = api.run(state=pyq.zero_state(2), values=f_params)
dfdx = torch.autograd.grad(wf, f_params["x"], torch.ones_like(wf))[0]

Documentation

!!! note Documentation in progress.

Contribute

Before making a contribution, please review our code of conduct.

• Submitting Issues: To submit bug reports or feature requests, please use our issue tracker.
• Developing in qadence 2 platforms: To learn more about how to develop within qadence 2 platforms, please refer to contributing guidelines.