Efficient Learning of Quantum States Prepared With Few Non-Clifford Gates

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Grewal, Sabee, Iyer, Vishnu, Kretschmer, William, Liang, Daniel
Formato: Preprint
Publicado: 2023
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866917065054486528
author Grewal, Sabee
Iyer, Vishnu
Kretschmer, William
Liang, Daniel
author_facet Grewal, Sabee
Iyer, Vishnu
Kretschmer, William
Liang, Daniel
contents We give a pair of algorithms that efficiently learn a quantum state prepared by Clifford gates and $O(\log n)$ non-Clifford gates. Specifically, for an $n$-qubit state $|ψ\rangle$ prepared with at most $t$ non-Clifford gates, our algorithms use $\mathsf{poly}(n,2^t,1/\varepsilon)$ time and copies of $|ψ\rangle$ to learn $|ψ\rangle$ to trace distance at most $\varepsilon$. The first algorithm for this task is more efficient, but requires entangled measurements across two copies of $|ψ\rangle$. The second algorithm uses only single-copy measurements at the cost of polynomial factors in runtime and sample complexity. Our algorithms more generally learn any state with sufficiently large stabilizer dimension, where a quantum state has stabilizer dimension $k$ if it is stabilized by an abelian group of $2^k$ Pauli operators. We also develop an efficient property testing algorithm for stabilizer dimension, which may be of independent interest.
format Preprint
id arxiv_https___arxiv_org_abs_2305_13409
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Efficient Learning of Quantum States Prepared With Few Non-Clifford Gates
Grewal, Sabee
Iyer, Vishnu
Kretschmer, William
Liang, Daniel
Quantum Physics
Machine Learning
We give a pair of algorithms that efficiently learn a quantum state prepared by Clifford gates and $O(\log n)$ non-Clifford gates. Specifically, for an $n$-qubit state $|ψ\rangle$ prepared with at most $t$ non-Clifford gates, our algorithms use $\mathsf{poly}(n,2^t,1/\varepsilon)$ time and copies of $|ψ\rangle$ to learn $|ψ\rangle$ to trace distance at most $\varepsilon$. The first algorithm for this task is more efficient, but requires entangled measurements across two copies of $|ψ\rangle$. The second algorithm uses only single-copy measurements at the cost of polynomial factors in runtime and sample complexity. Our algorithms more generally learn any state with sufficiently large stabilizer dimension, where a quantum state has stabilizer dimension $k$ if it is stabilized by an abelian group of $2^k$ Pauli operators. We also develop an efficient property testing algorithm for stabilizer dimension, which may be of independent interest.
title Efficient Learning of Quantum States Prepared With Few Non-Clifford Gates
topic Quantum Physics
Machine Learning
url https://arxiv.org/abs/2305.13409