Saved in:
Bibliographic Details
Main Authors: Anikin, Evgeny V., Chuchalin, Andrey, Donchenko, Dimitrii, Lakhmanskaya, Olga, Lakhmanskiy, Kirill
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2604.02301
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866918425770590208
author Anikin, Evgeny V.
Chuchalin, Andrey
Donchenko, Dimitrii
Lakhmanskaya, Olga
Lakhmanskiy, Kirill
author_facet Anikin, Evgeny V.
Chuchalin, Andrey
Donchenko, Dimitrii
Lakhmanskaya, Olga
Lakhmanskiy, Kirill
contents In trapped-ion chains, multipartite GHZ states can be prepared natively with the help of a single bichromatic laser pulse. However, higher-order terms in the expansion in the Lamb-Dicke parameter $η$ limit the GHZ state preparation infidelity for rectangular and bell-like pulses to the order of $η^4$. For tens of ions, the infidelity caused by out-of-Lamb-Dicke effects can reach several percents. We propose an amplitude and phase-modulated pulse shape, an "echoed lemniscate pulse", which cancels this contribution into error in the leading order. For the proposed pulse, the infidelity scales as $η^6$. The improved scaling is achieved because of a special phase trajectory of a collective motional mode following the figure-eight curve (lemniscate). We demonstrate that the lemniscate pulse allows achieving lower infidelity than bell-like pulses, which can be as low as $10^{-4}$ for $20$-ion chains.
format Preprint
id arxiv_https___arxiv_org_abs_2604_02301
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Lemniscate phase trajectories for high-fidelity GHZ state preparation in trapped-ion chains
Anikin, Evgeny V.
Chuchalin, Andrey
Donchenko, Dimitrii
Lakhmanskaya, Olga
Lakhmanskiy, Kirill
Quantum Physics
In trapped-ion chains, multipartite GHZ states can be prepared natively with the help of a single bichromatic laser pulse. However, higher-order terms in the expansion in the Lamb-Dicke parameter $η$ limit the GHZ state preparation infidelity for rectangular and bell-like pulses to the order of $η^4$. For tens of ions, the infidelity caused by out-of-Lamb-Dicke effects can reach several percents. We propose an amplitude and phase-modulated pulse shape, an "echoed lemniscate pulse", which cancels this contribution into error in the leading order. For the proposed pulse, the infidelity scales as $η^6$. The improved scaling is achieved because of a special phase trajectory of a collective motional mode following the figure-eight curve (lemniscate). We demonstrate that the lemniscate pulse allows achieving lower infidelity than bell-like pulses, which can be as low as $10^{-4}$ for $20$-ion chains.
title Lemniscate phase trajectories for high-fidelity GHZ state preparation in trapped-ion chains
topic Quantum Physics
url https://arxiv.org/abs/2604.02301