Release notes

What’s new in Qaptiva HPC 0.3.0

Released on March 2025

Qaptiva HPC Requirements

A HPC cluster with a compatible software stack:

  • Compute nodes with x86_64 support

  • RHEL 8 or 9, SLES 15 (or compatible OS)

  • Slurm scheduling system 23.02 (or above) with OpenMPI

  • Python version 3.9, 3.10, 3.11 or 3.12

A new distributed noisy emulator

Qaptiva HPC now features a distributed noisy emulator, DNoisy. It builds upon the the highly optimized distributed emulator DLinAlg and offers the same benefits of of multi-core (with OpenMP parallelism) and multi-nodes architectures, but will aditionally accept a hardware model describing the noise model to be applied to the circuit. DNoisy can then perform the exact simulation of such noisy quantum circuits by storing the entire density matrix describing the qubits’ state and distributing it across multiple nodes in a cluster, overcoming the memory limitation of a mono-node architecture.

A new distributed analog simulator

As of the present release, Qaptiva HPC now features a first analog simulator, called DMPSTraj. This emulator relies on a Matrix Product State (MPS) representation to perform the computation. It supports both ideal and noisy emulations. Because the noisy emulation is embarrassingly parallel, this emulator can use multiple nodes to emulate all the trajectories, and hence simulate even more qubits.

New compilation plugins

Qaptiva HPC provides new plugins to transpile a quantum circuits. These plugins can be divided in two categories:

  • plugins designed to execute a circuit on real quantum hardware.

  • plugins designed to perform emulation of quantum hardware.

Qaptiva HPC now provides transpilers to transform a quantum circuit into an equivalent one executable on a real quantum hardware. The transpiled circuit is not equal to the initial circuit but equivalent, meaning that result of the transpiled circuit may require classical processing to retrieve the expected result. Our transpilers are wrapped in plugins, like NISQCompiler, as plugins handle classical postprocessing automatically. Please refer to transpilation section to get more information on our transpilers tools.

Please note that are transpilers cannot transform circuits having more than 20 qubits. If you need to transpile bigger quantum circuits, please consider using a Qaptiva Appliance.

A new plugin RepairPermutation has been added in Qaptiva HPC. Its purpose is to return the qubits to their initial position at the end of a circuit that has been localized. This plugin is important for the new DNoisy emulator since it puts the state probabilities to be sampled back on the diagonal of the density matrix. It is applied by default by DNoisy after the Localizer plugin.

Updated features

  • DLinAlg updated features:

    • Now has an improved parallelism when sampling shots for nbshots > 0

    • Now does the sampling in place, so the number of qubits that can be simulated in SAMPLE mode and OBSERVABLE mode are now the same (No additional memory space needed for sampling)

    • Now supports observable mode with nbshots > 0

    • Removed qubit threshold for Localizer and FusionPlugin in the default plugins

  • CLinalg updated features:

    • Now supports string type psi_0.

    • Now supports observable mode with nbshots > 0 (no need to add ObservableSplitter anymore).

    • Observable mode with nbshots == 0 now sets value_data.

    • Now supports intermediate measurements in GPU simulation.

    • Now supports SAMPLE mode for nbshots > 0 in GPU simulation

  • FusionPlugin will now work even if the circuit contains gates that cannot be fused

Fixes

  • Fixed a segmentation fault in DLinAlg when sampling shots for nbshots > 0

  • Fixed an error in DLinAlg where SWAP gate was not working when there is only one local qubit

  • Fixed aligned_alloc/free in CLinalg on windows for diagonal gates

  • Fixed CUDA n-qbits gate in CLinalg

  • KPTree was generating wrong state prepartions if the state to prepare has a negative amplitude. The state preparation routine KPTree can now generate state preparations having negative real numbers.

First release of Qaptiva HPC

Version 0.1.0 released on July 2024

What is Qaptiva HPC

Qaptiva HPC is the distributed Quantum Appliance developed by Eviden. This appliance is meant to be deployed in a High-Performance Computing (HPC) environment with distributed resources, offering a highly optimized quantum circuit simulation with multithreading and state vector distribution. It features DLinAlg, a distributed Linear-algebra based simulator that extends the mono-node LinAlg simulator in Qaptiva to take advantage of multi-core (with OpenMP parallelism) and multi-nodes architectures. Message Passing Interface (MPI) protocol is used to handle communication between the distributed resources used to store and manipulate quantum states. This simulator offers the possibility to simulate larger circuits, as the complete representation of the state vector can be distributed across multiple nodes in a cluster, which allows us to overcome the memory limitation of a mono-node architecture.

Qaptiva HPC Requirements

A HPC cluster with a compatible software stack:

  • Compute nodes with AVX512 support (preferably)

  • RHEL 8 or 9 Operating System (preferably RHEL 9.4)

  • Slurm scheduling system 23.02 (or above)

  • Python version 3.9, 3.10, 3.11 or 3.12

  • OpenMPI version 4.1.5 or above

  • CUDA version 11.8 on RHEL 8, 12.4 on RHEL 9

  • Intel oneAPI MKL library