Pseudomagic Quantum States

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Gu, Andi, Leone, Lorenzo, Ghosh, Soumik, Eisert, Jens, Yelin, Susanne, Quek, Yihui
Format: Preprint
Published: 2023
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917678767144960
author Gu, Andi
Leone, Lorenzo
Ghosh, Soumik
Eisert, Jens
Yelin, Susanne
Quek, Yihui
author_facet Gu, Andi
Leone, Lorenzo
Ghosh, Soumik
Eisert, Jens
Yelin, Susanne
Quek, Yihui
contents Notions of nonstabilizerness, or "magic", quantify how non-classical quantum states are in a precise sense: states exhibiting low nonstabilizerness preclude quantum advantage. We introduce 'pseudomagic' ensembles of quantum states that, despite low nonstabilizerness, are computationally indistinguishable from those with high nonstabilizerness. Previously, such computational indistinguishability has been studied with respect to entanglement, introducing the concept of pseudoentanglement. However, we demonstrate that pseudomagic neither follows from pseudoentanglement nor implies it. In terms of applications, the study of pseudomagic offers fresh insights into the theory of quantum scrambling: it uncovers states that, even though they originate from non-scrambling unitaries, remain indistinguishable from scrambled states to any physical observer. Additional applications include new lower bounds on state synthesis problems, property testing protocols, and implications for quantum cryptography. Our work is driven by the observation that only quantities measurable by a computationally bounded observer - intrinsically limited by finite-time computational constraints - hold physical significance. Ultimately, our findings suggest that nonstabilizerness is a 'hide-able' characteristic of quantum states: some states are much more magical than is apparent to a computationally bounded observer.
format Preprint
id arxiv_https___arxiv_org_abs_2308_16228
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Pseudomagic Quantum States
Gu, Andi
Leone, Lorenzo
Ghosh, Soumik
Eisert, Jens
Yelin, Susanne
Quek, Yihui
Quantum Physics
Notions of nonstabilizerness, or "magic", quantify how non-classical quantum states are in a precise sense: states exhibiting low nonstabilizerness preclude quantum advantage. We introduce 'pseudomagic' ensembles of quantum states that, despite low nonstabilizerness, are computationally indistinguishable from those with high nonstabilizerness. Previously, such computational indistinguishability has been studied with respect to entanglement, introducing the concept of pseudoentanglement. However, we demonstrate that pseudomagic neither follows from pseudoentanglement nor implies it. In terms of applications, the study of pseudomagic offers fresh insights into the theory of quantum scrambling: it uncovers states that, even though they originate from non-scrambling unitaries, remain indistinguishable from scrambled states to any physical observer. Additional applications include new lower bounds on state synthesis problems, property testing protocols, and implications for quantum cryptography. Our work is driven by the observation that only quantities measurable by a computationally bounded observer - intrinsically limited by finite-time computational constraints - hold physical significance. Ultimately, our findings suggest that nonstabilizerness is a 'hide-able' characteristic of quantum states: some states are much more magical than is apparent to a computationally bounded observer.
title Pseudomagic Quantum States
topic Quantum Physics
url https://arxiv.org/abs/2308.16228