Imaginarity-generating power of unitaries: A resource-theoretic approach

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Awasthi, Akhil Kumar, Samanta, Mrinmoy, Mondal, Sudipta, Patra, Ayan, De, Aditi Sen
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911632282615808
author Awasthi, Akhil Kumar
Samanta, Mrinmoy
Mondal, Sudipta
Patra, Ayan
De, Aditi Sen
author_facet Awasthi, Akhil Kumar
Samanta, Mrinmoy
Mondal, Sudipta
Patra, Ayan
De, Aditi Sen
contents Imaginarity, stemming from the complex structure of quantum mechanics, has recently emerged as a fundamental resource, yet its dynamical generation remains largely unexplored. In this work, we introduce the notion of imaginarity-generating power (IGP) of unitary dynamics, which quantifies the ability of unitary operations to produce imaginarity from initially real quantum states. To quantify imaginarity, we employ a measure based on the Hilbert--Schmidt norm, which we show to be monotone under real unital operations. Within the framework of dynamical resource theories, we derive an exact expression for the purity-constrained IGP in arbitrary dimensions and show that, for pure real input states, it depends solely on intrinsic and experimentally accessible properties of the unitary. We further analyze its average behavior over ensembles of states with varying purity under both uniform and Hilbert--Schmidt distributions. We prove that it satisfies the essential properties of a valid resource monotone within the dynamical resource theory of imaginarity. We also characterize the unitaries that maximize the IGP and determine the corresponding bounds. Moreover, for Haar-random unitaries, we show that the IGP concentrates near its maximal value in high dimensions with small fluctuations, indicating that typical high-dimensional quantum dynamics are highly effective at generating imaginarity.
format Preprint
id arxiv_https___arxiv_org_abs_2604_26392
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Imaginarity-generating power of unitaries: A resource-theoretic approach
Awasthi, Akhil Kumar
Samanta, Mrinmoy
Mondal, Sudipta
Patra, Ayan
De, Aditi Sen
Quantum Physics
Mathematical Physics
Imaginarity, stemming from the complex structure of quantum mechanics, has recently emerged as a fundamental resource, yet its dynamical generation remains largely unexplored. In this work, we introduce the notion of imaginarity-generating power (IGP) of unitary dynamics, which quantifies the ability of unitary operations to produce imaginarity from initially real quantum states. To quantify imaginarity, we employ a measure based on the Hilbert--Schmidt norm, which we show to be monotone under real unital operations. Within the framework of dynamical resource theories, we derive an exact expression for the purity-constrained IGP in arbitrary dimensions and show that, for pure real input states, it depends solely on intrinsic and experimentally accessible properties of the unitary. We further analyze its average behavior over ensembles of states with varying purity under both uniform and Hilbert--Schmidt distributions. We prove that it satisfies the essential properties of a valid resource monotone within the dynamical resource theory of imaginarity. We also characterize the unitaries that maximize the IGP and determine the corresponding bounds. Moreover, for Haar-random unitaries, we show that the IGP concentrates near its maximal value in high dimensions with small fluctuations, indicating that typical high-dimensional quantum dynamics are highly effective at generating imaginarity.
title Imaginarity-generating power of unitaries: A resource-theoretic approach
topic Quantum Physics
Mathematical Physics
url https://arxiv.org/abs/2604.26392