Two measurement bases are asymptotically informationally complete for any pure state tomography

Fuente: arXiv
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Autori principali: Feng, Tianfeng, Xiao, Tianqi, Wang, Yu, Pang, Shengshi, Hanif, Farhan, Zhou, Xiaoqi, Zhao, Qi, Kim, M. S., Sun, Jinzhao
Natura: Preprint
Pubblicazione: 2025
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author Feng, Tianfeng
Xiao, Tianqi
Wang, Yu
Pang, Shengshi
Hanif, Farhan
Zhou, Xiaoqi
Zhao, Qi
Kim, M. S.
Sun, Jinzhao
author_facet Feng, Tianfeng
Xiao, Tianqi
Wang, Yu
Pang, Shengshi
Hanif, Farhan
Zhou, Xiaoqi
Zhao, Qi
Kim, M. S.
Sun, Jinzhao
contents One of the fundamental questions in quantum information theory is to find how many measurement bases are required to obtain the full information of a quantum state. While a minimum of four measurement bases is typically required to determine an arbitrary pure state, we prove that for any states generated by finite-depth Clifford + T circuits, just two measurement bases are sufficient. More generally, we prove that two measurement bases are informationally complete for determining algebraic pure states whose state-vector elements represented in the computational basis are algebraic numbers. Since any pure state can be asymptotically approximated by a sequence of algebraic states with arbitrarily high precision, our scheme is referred to as asymptotically informationally complete for pure state tomography. Furthermore, existing works mostly construct the measurements using entangled bases. So far, the best result requires $O(n)$ local measurement bases for $n$-qubit pure-state tomography. Here, we show that two measurement bases that involve polynomial elementary gates are sufficient for uniquely determining sparse algebraic states. Moreover, we prove that two local measurement bases, involving single-qubit local operations only, are informationally complete for certain algebraic states, such as GHZ-like and W-like states. Besides, our two-measurement-bases scheme remains valid for mixed states with certain types of noises. We numerically test the uniqueness of the reconstructed states under two (local) measurement bases with and without measurement and depolarising types of noise. Our scheme provides a theoretical guarantee for pure state tomography in the fault-tolerant quantum computing regime.
format Preprint
id arxiv_https___arxiv_org_abs_2501_17061
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Two measurement bases are asymptotically informationally complete for any pure state tomography
Feng, Tianfeng
Xiao, Tianqi
Wang, Yu
Pang, Shengshi
Hanif, Farhan
Zhou, Xiaoqi
Zhao, Qi
Kim, M. S.
Sun, Jinzhao
Quantum Physics
Mathematical Physics
Data Analysis, Statistics and Probability
One of the fundamental questions in quantum information theory is to find how many measurement bases are required to obtain the full information of a quantum state. While a minimum of four measurement bases is typically required to determine an arbitrary pure state, we prove that for any states generated by finite-depth Clifford + T circuits, just two measurement bases are sufficient. More generally, we prove that two measurement bases are informationally complete for determining algebraic pure states whose state-vector elements represented in the computational basis are algebraic numbers. Since any pure state can be asymptotically approximated by a sequence of algebraic states with arbitrarily high precision, our scheme is referred to as asymptotically informationally complete for pure state tomography. Furthermore, existing works mostly construct the measurements using entangled bases. So far, the best result requires $O(n)$ local measurement bases for $n$-qubit pure-state tomography. Here, we show that two measurement bases that involve polynomial elementary gates are sufficient for uniquely determining sparse algebraic states. Moreover, we prove that two local measurement bases, involving single-qubit local operations only, are informationally complete for certain algebraic states, such as GHZ-like and W-like states. Besides, our two-measurement-bases scheme remains valid for mixed states with certain types of noises. We numerically test the uniqueness of the reconstructed states under two (local) measurement bases with and without measurement and depolarising types of noise. Our scheme provides a theoretical guarantee for pure state tomography in the fault-tolerant quantum computing regime.
title Two measurement bases are asymptotically informationally complete for any pure state tomography
topic Quantum Physics
Mathematical Physics
Data Analysis, Statistics and Probability
url https://arxiv.org/abs/2501.17061