Quantum Brain
← Back to papers

GroupFunctions.jl: computing individual entries of the irreducible representations of the unitary group U(d)

David Amaro-Alcalá, Konrad Szymański·July 12, 2026
Quantum Physicscs.MS

AI Breakdown

Get a structured breakdown of this paper — what it's about, the core idea, and key takeaways for the field.

Abstract

GroupFunctions.jl is a Julia library for computing individual matrix elements of irreducible representations of U(d). These matrix elements, called group functions, can be evaluated symbolically or numerically. For SU(2), they reduce to the Wigner D-functions. The library computes these matrix elements in a carrier-space basis enumerated by Gelfand-Tsetlin patterns. It can also compute entire representation operators, construct input unitaries from parameterisations common in quantum optics, translate Gelfand-Tsetlin patterns into occupation-number kets, and compute the associated Schur functions. Results can be exported in a form compatible with Mathematica.

Related Research

Quantum Intelligence

Ask about quantum research, companies, or market developments.