Carcará

Carcará is a framework for fermionic quantum simulation based on variational quantum algorithms, engineered from the ground up for deployment on real quantum hardware.

Overview

Carcará connects theoretical condensed matter physics with NISQ-era quantum hardware. Engineered around variational workflows, the framework streamlines the pipeline from mapping complex fermionic Hamiltonians onto qubit operators to optimizing ansatz states and executing error-mitigated circuits on real quantum backends.

Key Features

• Fermion-to-Qubit Mapping: Built-in, optimized transformations including Jordan-Wigner, Bravyi-Kitaev, and parity mappings to translate fermionic creation/annihilation operators into Pauli strings.

• Hardware-Efficient & Physics-Inspired Ansatzes: Ready-to-use ansatz generation, including Unitary Coupled Cluster (UCCSD) and hardware-efficient templates designed to minimize circuit depth and gate errors on real QPUs.

• Hybrid Variational Solvers: Robust implementation of the Variational Quantum Eigensolver (VQE) and its time-dependent variants, coupled with state-of-the-art classical optimizers (e.g., SPSA, COBYLA, SLSQP).

• Real Hardware Deployment: Seamless integration with major quantum cloud providers (IBM Quantum Platform) with native support.

• Advanced Error Mitigation: Built-in noise-resilient pipelines featuring Zero-Noise Extrapolation (ZNE) and symmetry verification.

Installation

From pip

The easiest way to install Carcará is with pip:

pip install carcara

From github

To install Carcará directly from the GitHub repository, run the following commands:

git clone https://github.com/seixas-research/carcara.git
cd carcara
pip install -e .

Getting started

License

This is an open source code under MIT License.

Acknowledgements

We thank financial support from INCT Materials Informatics (Grant No. 406447/2022-5).