QoolQit

How does QoolQit relate to Pulser?

QoolQit and Pulser are complementary frameworks that support different levels of abstraction.

QoolQit is designed for users who want to focus on analog quantum program design and algorithmic workflows without working directly with every hardware-level parameter. Pulser is intended for users who require more detailed, physics-informed control over atom register layouts, pulse-level programming, device specifications, control channels, and hardware parameters.

QoolQit is therefore not a replacement for Pulser. It offers a higher-level entry point for developing analog quantum programs within the Pasqal Software Stack.

Can QoolQit be used in hybrid classical–quantum workflows?

Yes. QoolQit can be integrated into hybrid classical–quantum workflows, where classical computation is used to define, update, or optimize elements of a quantum program, and emulation or quantum execution is used to evaluate the results.

For example, a classical optimizer can iteratively update an atom layout or other program inputs. When an update changes a compiled register, the program must be recompiled before it is run on the selected backend.

Can I iteratively optimize an atom layout in QoolQit?

Yes. The embedding stage provides the coordinates used to instantiate an atom register, and those coordinates can be updated as part of an iterative workflow.

You can revise the layout before compilation or recompile the program after a register update. This makes it possible to incorporate embedding and layout optimisation into a broader classical–quantum development loop.

What is the difference between a target device and an execution backend?

A target device describes the neutral-atom system for which a quantum program is compiled, including its relevant specifications and constraints. An execution backend is the resource used to run that compiled program. Depending on availability and compatibility, this may be physical quantum hardware or an emulator. If you decide to run your program on a physical quantum hardware, the notion of backend and device coincide! Therefore, make sure that the program has been compiled using the device/backend that you want to use to run.

Can QoolQit programs be emulated?

Yes. QoolQit programs can be developed and validated with emulators before execution on quantum hardware. The Pasqal Software Stack supports local emulation for development on a laptop, as well as remote emulation resources through Pasqal Cloud for larger-scale simulation needs

Can embedding affect the optimal solutions of a QUBO problem?

Yes. Embedding maps an abstract optimisation problem onto a physical atom layout and may approximate the original QUBO matrix. When the approximation is not exact, the embedded Hamiltonian may not preserve every optimal assignment of the original problem.

For this reason, embedding quality should be assessed both by comparing the target and embedded problem representations and by evaluating whether the workflow can recover the relevant optimal or low-energy solutions.

How does analog quantum programming compare with gate-based quantum computing?

Analog neutral-atom platforms are well suited to implementing time-dependent Hamiltonian evolutions directly, including approaches used in adiabatic quantum optimisation. In gate-based quantum computing, comparable dynamics are generally approximated by decomposing the evolution into a sequence of quantum gates. The analog approach does not imply a universal performance advantage. Results depend on the problem, encoding, algorithm, hardware characteristics, noise, and classical baseline. The suitability of an analog approach should therefore be evaluated for the specific use case.

Where can I learn more and get started with QoolQit?

The QoolQit documentation is the best place to start for installation guidance, concepts, examples, and quantum-application notebooks. You can also explore the QoolQit learning materials we shared throughout the QoolQit beta testing program, which cover graph embedding, registers and drives, compilation and execution, and QUBO workflows. In this GitHub repository you can find exercises and their solutions.

Does QoolQit support non-adiabatic waveforms?

In QoolQit users can directly create waveforms and specify their duration. So, yes a user can also create from scratch non-adiabatic evolutions.

We are also exploring ways to expand the available waveform library over time. If you are working with a particular non-adiabatic protocol or waveform family, we welcome your feedback through the QoolQit community and open-source channels.