Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:2305.09757 · Physical Review X

Robust Hamiltonian Engineering for Interacting Qudit Systems

Hengyun Zhou, Haoyang Gao, Nathaniel Leitao, Oksana Makarova, Iris Cong, Alexander M. Douglas, Leigh S. Martin, Mikhail D. Lukin

Published Jul 31, 2024• 25 citations
arXivHTMLPDF

Abstract

Dynamical decoupling and Hamiltonian engineering are well-established techniques that have been used to control qubit systems. However, designing the corresponding methods for qudit systems has been challenging due to the lack of a Bloch sphere representation, more complex interactions, and additional control constraints. By identifying several general structures associated with such problems, we develop a formalism for the robust dynamical decoupling and Hamiltonian engineering of strongly interacting qudit systems. Our formalism significantly simplifies qudit pulse-sequence design while naturally incorporating robustness conditions necessary for experimental practicality. We experimentally demonstrate these techniques in a strongly interacting, disordered ensemble of spin-1 nitrogen-vacancy centers, achieving more than an order-of-magnitude improvement in coherence time over existing pulse sequences. We further describe how our techniques enable the engineering of exotic many-body phenomena such as quantum many-body scars, and open up new opportunities for quantum metrology with enhanced sensitivities. These results enable wide-reaching new applications for dynamical decoupling and Hamiltonian engineering in many-body physics and quantum metrology. Published by the American Physical Society 2024

DOI
10.1103/physrevx.14.031017

Related papers

Quantum Many-Body Physics and Quantum Metrology with Floquet-Engineered Interacting Spin Systems

Hengyun Zhou

Improved control and manipulation of quantum systems lies at the heart of modern quantum science and technology, with broad applications ranging from quantum metrology to quantum information science and many-body physics. In this thesis, I will introduce a novel framework for robust Hamiltonian engineering in interacting spin systems, which enables the efficient design of Floquet engineering pulse sequences for qubit and qudit systems that out-perform state-of-the-art control methods by orders of magnitude. As applications of this framework, we utilize a high density ensemble of nitrogen vacancy (NV) centers in diamond, and demonstrate significantly improved control over the disordered, interacting many-body spin system. This enabled the first solid state spin ensemble quantum sensor operating beyond the sensitivity limit imposed by interactions between sensing particles, as well as the observation and understanding of novel dynamical many-body phenomena, including discrete time crystalline order and thermalization dynamics in long-range interacting XXZ spin models.

•Jan 1, 2022•0 citations

Robust Higher-Order Hamiltonian Engineering for Quantum Sensing with Strongly Interacting Systems

Hengyun Zhou, Leigh S. Martin, Matthew Tyler +4 more

Dynamical decoupling techniques constitute an integral part of many quantum sensing platforms, often leading to orders-of-magnitude improvements in coherence time and sensitivity. Most ac sensing sequences involve a periodic echolike structure, in which the target signal is synchronized with the echo period. We show that for strongly interacting systems, this construction leads to a fundamental sensitivity limit associated with imperfect interaction decoupling. We present a simple physical picture demonstrating the origin of this limitation, and further formalize these considerations in terms of concise higher-order decoupling rules. We then show how these limitations can be surpassed by identifying a novel sequence building block, in which the signal period matches twice the echo period. Using these decoupling rules and the resulting sequence building block, we experimentally demonstrate significant improvements in dynamical decoupling timescales and magnetic field sensitivity, opening the door for new applications in quantum sensing and quantum many-body physics.

arXiv:2303.07363•Physical Review Letters•Dec 1, 2023•24 citations

Robust Hamiltonian engineering with subensemble control

Wenjie Gong, Matteo Votto, Soonwon Choi

We present a robust protocol to reshape interactions in a spin ensemble based on global control pulse sequences applied to multiple subensembles in parallel. This setting arises naturally from ensembles of solid-state defects or multi-species atomic arrays. We show that it is provably computationally hard to find pulse sequences that simultaneously engineer interactions both within and between subensembles. Despite its formal hardness, we identify a set of necessary or sufficient conditions under which one can synthesize a target Hamiltonian from the native one. Moreover, we introduce efficient numerical strategies for designing pulse sequences that engineer target Hamiltonians robust against common control imperfections. As a specific application, we discuss the robust generation of two-mode spin squeezing in dual-species atomic ensembles, which is a challenging task without subensemble control. Our results provide a practical toolbox to design novel quantum simulation and sensing experiments with minimal control overhead.

quant-pharXiv:2609.03045•Sep 4, 2026•0 citations

Dynamical Engineering of Interactions in Qudit Ensembles

Soonwon Choi, Norman Y. Yao, Mikhail D. Lukin

We propose and analyze a method to engineer effective interactions in an ensemble of d-level systems (qudits) driven by global control fields. In particular, we present (i) a necessary and sufficient condition under which a given interaction can be decoupled, (ii) the existence of a universal sequence that decouples any (cancelable) interaction, and (iii) an efficient algorithm to engineer a target Hamiltonian from an initial Hamiltonian (if possible). We illustrate the potential of this method with two examples. Specifically, we present a 6-pulse sequence that decouples effective spin-1 dipolar interactions and demonstrate that a spin-1 Ising chain can be engineered to study transitions among three distinct symmetry protected topological phases. Our work enables new approaches for the realization of both many-body quantum memories and programmable analog quantum simulators using existing experimental platforms.

arXiv:1703.09808•Physical Review Letters•Nov 3, 2017•53 citations

Engineering Higher-order Effective Hamiltonians

Jiahui Chen, David Cory

Advancing quantum technologies requires precise and robust coherent control of quantum systems. Robust higher-order Hamiltonian engineering is essential for high-precision control and for accessing effective dynamics absent at zeroth order. Here, we introduce a systematic methodology for achieving the precision, robustness, and complexity required for quantum control through the engineering of higher-order processes and effective Hamiltonians. We identify the minimal subspace of achievable effective Hamiltonian at each order and provide universal cost functions for achieving desired targets. Examples include robust sequences for decoupling, three-body interactions and detuning/interaction correlations.

quant-pharXiv:2603.11185•Mar 13, 2026•0 citations

Advanced Hamiltonian engineering in spin ensembles for enhanced sensing and control

Kevin I. O. Ben'Attar, Yachel Ben-Shalom, Genko T. Genov +4 more

The study of many-body quantum systems, and specifically spin systems, is a main pillar of quantum physics. As part of this research direction, various experimental platforms have emerged which allow for controlled experiments in this context, with nitrogen vacancy (NV) ensembles in diamond being one of them. In order to realize relevant experiments in the NV system, advanced controlled schemes are required in order to generate the required interacting spin Hamiltonians, as well as to robustly control such dense spin ensembles. Here we tackle both issues: we develop a framework for Hamiltonian engineering based on the icosahedral symmetry group, demonstrating its advantages over existing schemes in terms of obtainable interacting Hamiltonians; we develop and demonstrate robust control pulses based on rapid adiabatic passage (RAP), which result in improved coherence times and sensing.

Optical and Quantum Sensing and Precision Metrology II•Feb 25, 2020•0 citations
Dynamical decoupling and Hamiltonian engineering are well-established techniques that have been used to control qubit systems. However, designing the corresponding methods for qudit systems has been challenging due to the lack of a Bloch sphere representation, more complex interactions, and additional control constraints. By identifying several general structures associated with such problems, we develop a formalism for the robust dynamical decoupling and Hamiltonian engineering of strongly interacting qudit systems. Our formalism significantly simplifies qudit pulse-sequence design while naturally incorporating robustness conditions necessary for experimental practicality. We experimentally demonstrate these techniques in a strongly interacting, disordered ensemble of spin-1 nitrogen-vacancy centers, achieving more than an order-of-magnitude improvement in coherence time over existing pulse sequences. We further describe how our techniques enable the engineering of exotic many-body phenomena such as quantum many-body scars, and open up new opportunities for quantum metrology with enhanced sensitivities. These results enable wide-reaching new applications for dynamical decoupling and Hamiltonian engineering in many-body physics and quantum metrology. Published by the American Physical Society 2024
Improved control and manipulation of quantum systems lies at the heart of modern quantum science and technology, with broad applications ranging from quantum metrology to quantum information science and many-body physics. In this thesis, I will introduce a novel framework for robust Hamiltonian engineering in interacting spin systems, which enables the efficient design of Floquet engineering pulse sequences for qubit and qudit systems that out-perform state-of-the-art control methods by orders of magnitude. As applications of this framework, we utilize a high density ensemble of nitrogen vacancy (NV) centers in diamond, and demonstrate significantly improved control over the disordered, interacting many-body spin system. This enabled the first solid state spin ensemble quantum sensor operating beyond the sensitivity limit imposed by interactions between sensing particles, as well as the observation and understanding of novel dynamical many-body phenomena, including discrete time crystalline order and thermalization dynamics in long-range interacting XXZ spin models.
Dynamical decoupling techniques constitute an integral part of many quantum sensing platforms, often leading to orders-of-magnitude improvements in coherence time and sensitivity. Most ac sensing sequences involve a periodic echolike structure, in which the target signal is synchronized with the echo period. We show that for strongly interacting systems, this construction leads to a fundamental sensitivity limit associated with imperfect interaction decoupling. We present a simple physical picture demonstrating the origin of this limitation, and further formalize these considerations in terms of concise higher-order decoupling rules. We then show how these limitations can be surpassed by identifying a novel sequence building block, in which the signal period matches twice the echo period. Using these decoupling rules and the resulting sequence building block, we experimentally demonstrate significant improvements in dynamical decoupling timescales and magnetic field sensitivity, opening the door for new applications in quantum sensing and quantum many-body physics.
We present a robust protocol to reshape interactions in a spin ensemble based on global control pulse sequences applied to multiple subensembles in parallel. This setting arises naturally from ensembles of solid-state defects or multi-species atomic arrays. We show that it is provably computationally hard to find pulse sequences that simultaneously engineer interactions both within and between subensembles. Despite its formal hardness, we identify a set of necessary or sufficient conditions under which one can synthesize a target Hamiltonian from the native one. Moreover, we introduce efficient numerical strategies for designing pulse sequences that engineer target Hamiltonians robust against common control imperfections. As a specific application, we discuss the robust generation of two-mode spin squeezing in dual-species atomic ensembles, which is a challenging task without subensemble control. Our results provide a practical toolbox to design novel quantum simulation and sensing experiments with minimal control overhead.
We propose and analyze a method to engineer effective interactions in an ensemble of d-level systems (qudits) driven by global control fields. In particular, we present (i) a necessary and sufficient condition under which a given interaction can be decoupled, (ii) the existence of a universal sequence that decouples any (cancelable) interaction, and (iii) an efficient algorithm to engineer a target Hamiltonian from an initial Hamiltonian (if possible). We illustrate the potential of this method with two examples. Specifically, we present a 6-pulse sequence that decouples effective spin-1 dipolar interactions and demonstrate that a spin-1 Ising chain can be engineered to study transitions among three distinct symmetry protected topological phases. Our work enables new approaches for the realization of both many-body quantum memories and programmable analog quantum simulators using existing experimental platforms.
Advancing quantum technologies requires precise and robust coherent control of quantum systems. Robust higher-order Hamiltonian engineering is essential for high-precision control and for accessing effective dynamics absent at zeroth order. Here, we introduce a systematic methodology for achieving the precision, robustness, and complexity required for quantum control through the engineering of higher-order processes and effective Hamiltonians. We identify the minimal subspace of achievable effective Hamiltonian at each order and provide universal cost functions for achieving desired targets. Examples include robust sequences for decoupling, three-body interactions and detuning/interaction correlations.
The study of many-body quantum systems, and specifically spin systems, is a main pillar of quantum physics. As part of this research direction, various experimental platforms have emerged which allow for controlled experiments in this context, with nitrogen vacancy (NV) ensembles in diamond being one of them. In order to realize relevant experiments in the NV system, advanced controlled schemes are required in order to generate the required interacting spin Hamiltonians, as well as to robustly control such dense spin ensembles. Here we tackle both issues: we develop a framework for Hamiltonian engineering based on the icosahedral symmetry group, demonstrating its advantages over existing schemes in terms of obtainable interacting Hamiltonians; we develop and demonstrate robust control pulses based on rapid adiabatic passage (RAP), which result in improved coherence times and sensing.