A compact Linear Combination of Unitaries framework that leverages the check matrix formalism to implement a constant-depth SELECT oracle using only singly controlled Pauli gates and ancillae. By further exploiting problem structure and introducing efficient Dicke state preparation routines, we achieve significant reductions in gate complexity, enabling practical block encodings for structured Hamiltonians such as Heisenberg and spin glass models.
All the 🦊-LCU block encoding scripts make use of Qiskit. To run the tests, first install the package in editable mode with development dependencies:
pip install -e .All the 🦊-LCU block encoding scripts make use of the QCLAB toolbox, which requires MATLAB R2021a or newer. Detailed download installation instructions can be found here.
Cite the following reference for 🦊-LCU:
F. Della Chiara, M. Nibbi, Y. Shen, R. Van Beeumen, Efficient LCU block encodings through Dicke states preparation, Daan Camps, Roel Van Beeumen, 2025, arXiv:2507.20887.