Optimal algorithms for materializing stabilizer states and Clifford gates from compact descriptions

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Cha, Hyunho, Lee, Jungwoo
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913038910619648
author Cha, Hyunho
Lee, Jungwoo
author_facet Cha, Hyunho
Lee, Jungwoo
contents Stabilizer states admit compact classical descriptions, but many downstream tasks still require their full amplitude vectors. Since the output itself has size $2^n$, the main algorithmic question is whether one can materialize an $n$-qubit stabilizer state vector in optimal $O(2^n)$ time, rather than paying an additional polynomial overhead. We answer this question in the affirmative. Starting from the standard quadratic-form representation of stabilizer states, we give an algorithm that runs in $O(2^n)$ time and $O(2^n)$ space. The idea is to maintain a cached parity word that records all future off-diagonal quadratic phase increments simultaneously. As consequences, we obtain an optimal procedure for materializing a stabilizer state vector from a standard check-matrix description, and an optimal algorithm for expanding a Clifford tableau into its full dense matrix. These results close the asymptotic gap for dense stabilizer and Clifford materialization.
format Preprint
id arxiv_https___arxiv_org_abs_2604_15405
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Optimal algorithms for materializing stabilizer states and Clifford gates from compact descriptions
Cha, Hyunho
Lee, Jungwoo
Quantum Physics
Stabilizer states admit compact classical descriptions, but many downstream tasks still require their full amplitude vectors. Since the output itself has size $2^n$, the main algorithmic question is whether one can materialize an $n$-qubit stabilizer state vector in optimal $O(2^n)$ time, rather than paying an additional polynomial overhead. We answer this question in the affirmative. Starting from the standard quadratic-form representation of stabilizer states, we give an algorithm that runs in $O(2^n)$ time and $O(2^n)$ space. The idea is to maintain a cached parity word that records all future off-diagonal quadratic phase increments simultaneously. As consequences, we obtain an optimal procedure for materializing a stabilizer state vector from a standard check-matrix description, and an optimal algorithm for expanding a Clifford tableau into its full dense matrix. These results close the asymptotic gap for dense stabilizer and Clifford materialization.
title Optimal algorithms for materializing stabilizer states and Clifford gates from compact descriptions
topic Quantum Physics
url https://arxiv.org/abs/2604.15405