Simulation of exceptional-point systems on quantum computers for quantum sensing

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Waghela, Chetan, Dasgupta, Shubhrangshu
Natura: Preprint
Pubblicazione: 2023
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866913192885616640
author Waghela, Chetan
Dasgupta, Shubhrangshu
author_facet Waghela, Chetan
Dasgupta, Shubhrangshu
contents There has been debate around applicability of exceptional points (EP) for quantum sensing. To resolve this, we first explore how to experimentally implement the nonhermitian non-diagonalizable Hamiltonians, that exhibit EPs, in quantum computers which run on unitary gates. We propose to use an ancilla-based method in this regard. Next, we show how such Hamiltonians can be used for parameter estimation using quantum computers and analyze its performance in terms of the Quantum Fisher Information ($QFI$) at EPs, both without noise and in presence of noise. It is well known that $QFI$ of a parameter to be estimated is inversely related to the variance of the parameter by the quantum Cramer-Rao bound. Therefore the divergence of the $QFI$ at EPs promise sensing advantages. We experimentally demonstrate in a cloud quantum architecture and theoretically show, using Puiseux series, that the $QFI$ indeed diverges in such EP systems which were earlier considered to be non-divergent.
format Preprint
id arxiv_https___arxiv_org_abs_2304_12181
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Simulation of exceptional-point systems on quantum computers for quantum sensing
Waghela, Chetan
Dasgupta, Shubhrangshu
Quantum Physics
There has been debate around applicability of exceptional points (EP) for quantum sensing. To resolve this, we first explore how to experimentally implement the nonhermitian non-diagonalizable Hamiltonians, that exhibit EPs, in quantum computers which run on unitary gates. We propose to use an ancilla-based method in this regard. Next, we show how such Hamiltonians can be used for parameter estimation using quantum computers and analyze its performance in terms of the Quantum Fisher Information ($QFI$) at EPs, both without noise and in presence of noise. It is well known that $QFI$ of a parameter to be estimated is inversely related to the variance of the parameter by the quantum Cramer-Rao bound. Therefore the divergence of the $QFI$ at EPs promise sensing advantages. We experimentally demonstrate in a cloud quantum architecture and theoretically show, using Puiseux series, that the $QFI$ indeed diverges in such EP systems which were earlier considered to be non-divergent.
title Simulation of exceptional-point systems on quantum computers for quantum sensing
topic Quantum Physics
url https://arxiv.org/abs/2304.12181