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

Physical Review A

Coupled dynamics of spin qubits in optical dipole microtraps: Application to the error analysis of a Rydberg-blockade gate

L. V. Gerasimov, R. R. Yusupov, A. D. Moiseevskiy, Ivan Vybornyi, K. S. Tikhonov, S. P. Kulik, Stanislav S. Straupe, Charles I. Sukenik, Dmitriy V. Kupriyanov

Published Oct 7, 2022• 7 citations
Publisher

Abstract

Single atoms in dipole microtraps or optical tweezers have recently become a promising platform for quantum computing and simulation. Here we report a detailed theoretical analysis of the physics underlying an implementation of a Rydberg two-qubit gate in such a system---a cornerstone protocol in quantum computing with single atoms. We focus on a blockade-type entangling gate and consider various decoherence processes limiting its performance in a real system. We provide numerical estimates for the limits on fidelity of the maximally entangled states and predict the full process matrix corresponding to the noisy two-qubit gate. We consider different excitation geometries and show certain advantages for the gate realization with linearly polarized driving beams. Our methods and results may find implementation in numerical models for simulation and optimization of neutral atom based quantum processors.

DOI
10.1103/physreva.106.042410

Related papers

Coupled dynamics of spin qubits in optical dipole microtraps

L. V. Gerasimov, R. R. Yusupov, A. D. Moiseevskiy +6 more

Single atoms in dipole microtraps or optical tweezers have recently become a promising platform for quantum computing and simulation. Here we report a detailed theoretical analysis of the physics underlying an implementation of a Rydberg two-qubit gate in such a system -- a cornerstone protocol in quantum computing with single atoms. We focus on a blockade-type entangling gate and consider various decoherence processes limiting its performance in a real system. We provide numerical estimates for the limits on fidelity of the maximally entangled states and predict the full process matrix corresponding to the noisy two-qubit gate. Our methods and results may find implementation in numerical models for simulation and optimization of neutral atom based quantum processors.

arXiv:2205.03383•May 6, 2022•0 citations

Optimization of Entangling Logic Gates Based on the Rydberg Blockade Effect

L. V. Gerasimov, Dmitriy V. Kupriyanov, Stanislav S. Straupe

The implementation of a quantum logic gate in a system of cold atoms in optical microtraps is analyzed. The dynamics of two spin qubits is simulated, and a number of processes that limit the efficiency of entanglement based on the Rydberg blockade effect are considered. A geometry of two-photon excitation of Rydberg states of atoms is proposed that makes it possible to increase the robustness of the system to variations in a number of parameters and to reduce losses associated with the incoherent scattering of the driving field.

Журнал Экспериментальной и Теоретической Физики•Dec 15, 2023•0 citations

Optimization of Entangling Logic Gates Based on the Rydberg Blockade Effect

L. V. Gerasimov, Dmitriy V. Kupriyanov, Stanislav S. Straupe

Abstract The implementation of a quantum logic gate in a system of cold atoms in optical microtraps is analyzed. The dynamics of two spin qubits is simulated, and a number of processes that limit the efficiency of entanglement based on the Rydberg blockade effect are considered. A geometry of two-photon excitation of Rydberg states of atoms is proposed that makes it possible to increase the robustness of the system to variations in a number of parameters and to reduce losses associated with the incoherent scattering of the driving field.

Journal of Experimental and Theoretical Physics•Aug 1, 2023•1 citation

Optimal quantum gates \nfor Rydberg atoms quantum computer

Pagano, Alice

Arrays of identical neutral atoms trapped in optical tweezers are a promising candidate for use in quantum computing. These platforms are highly scalable to large numbers of qubits and neutral atoms boost several attractive features as long coherence times and the possibility to be entangled via strong dipole-dipole interactions by driving them to highly excited Rydberg states. \nThe Thesis work is developed inside the framework of the QRydDemo project, whose aim in the next few years is to realize a neutral atom quantum processor with several hundred qubits. The smallest building blocks for the quantum computer are one and two-qubit gates: to entangle two atoms in the quantum register, a controlled-phase (CZ) gate will be implemented by shining fine-tuned laser pulses onto them. In this work, after giving a theoretical description of the Hamiltonian of two neutral atoms in the quantum register, a numerical simulation of this system is exploited to reproduce the behavior of the two-qubit CZ gate. Realistic effects are taken into account as finite temperature, imperfect Rydberg blockade, or decay out of the Rydberg state. A protocol with constant pulses is analyzed and its optimal parameters are found through classical optimizers. Then, time-dependent pulses are introduced and the optimal pulses are found through the optimal control algorithm dCRAB in an open-loop optimization. For the experimental realization of the gate, this analysis is of pivotal importance to know in which aspect more effort has to be put to maximize the experimental precision of the operation and thus improving the performance of the whole device \n

•Sep 1, 2021•0 citations

Towards High Fidelity Quantum Computation and Simulation with Rydberg Atoms

Anant Kale

Individually trapped neutral atoms are a promising candidate for use in quantum computing and simulation applications. They are highly scalable, have long coherence times and can be entangled via strong dipole-dipole interactions by driving to highly excited Rydberg states. However, the fidelity of single atom operations as well as two-atom entangling operations is limited by intrinsic sources of decoherence such as atomic motion, as well as technical sources of noise such as laser intensity fluctuations and phase/frequency fluctuations. We study the effect of these factors on single atom Rabi oscillations and two-atom Rydberg blockaded Rabi oscillations, using perturbation theory and numerical simulation. We develop a window function approach which helps us qualitatively understand the significance of the different spectral components of the noise as well as quantitatively understand the dependence of the Rabi oscillation fidelity on Rabi frequency. This allows us to predict the maximum experimentally achievable fidelities using independent measurements of experimental parameters such as noise spectra and atomic temperature. Turning to the question of near-term scalability of the experimental system, we prototype and test a method of generating a ’ladder’ configuration of optical tweezers utilizing two independent lasers. Our setup allows us to fully tune the geometry of the ladder, namely the separation between the two rows, the angle between them, and their relative position along the axis of the ladder. This pseudo-2D configuration enables us to reach larger system sizes in the near future and allows us to access beyond 1D physics.

•Jun 1, 2020•1 citation

Analysis of a quantum logic device based on dipole-dipole interactions of optically trapped Rydberg atoms

Mark E. Saffman, Thad G Walker

We present a detailed analysis and design of a neutral atom quantum logic device based on atoms in optical traps interacting via dipole-dipole coupling of Rydberg states. The dominant physical mechanisms leading to decoherence and loss of fidelity are enumerated. Our results support the feasibility of performing single- and two-qubit gates at MHz rates with decoherence probability and fidelity errors at the level of ${10}^{\ensuremath{-}3}$ for each operation. Current limitations and possible approaches to further improvement of the device are discussed.

arXiv:quant-ph/0502051•Physical Review A•Aug 31, 2005•278 citations
Single atoms in dipole microtraps or optical tweezers have recently become a promising platform for quantum computing and simulation. Here we report a detailed theoretical analysis of the physics underlying an implementation of a Rydberg two-qubit gate in such a system---a cornerstone protocol in quantum computing with single atoms. We focus on a blockade-type entangling gate and consider various decoherence processes limiting its performance in a real system. We provide numerical estimates for the limits on fidelity of the maximally entangled states and predict the full process matrix corresponding to the noisy two-qubit gate. We consider different excitation geometries and show certain advantages for the gate realization with linearly polarized driving beams. Our methods and results may find implementation in numerical models for simulation and optimization of neutral atom based quantum processors.
Single atoms in dipole microtraps or optical tweezers have recently become a promising platform for quantum computing and simulation. Here we report a detailed theoretical analysis of the physics underlying an implementation of a Rydberg two-qubit gate in such a system -- a cornerstone protocol in quantum computing with single atoms. We focus on a blockade-type entangling gate and consider various decoherence processes limiting its performance in a real system. We provide numerical estimates for the limits on fidelity of the maximally entangled states and predict the full process matrix corresponding to the noisy two-qubit gate. Our methods and results may find implementation in numerical models for simulation and optimization of neutral atom based quantum processors.
The implementation of a quantum logic gate in a system of cold atoms in optical microtraps is analyzed. The dynamics of two spin qubits is simulated, and a number of processes that limit the efficiency of entanglement based on the Rydberg blockade effect are considered. A geometry of two-photon excitation of Rydberg states of atoms is proposed that makes it possible to increase the robustness of the system to variations in a number of parameters and to reduce losses associated with the incoherent scattering of the driving field.
Abstract The implementation of a quantum logic gate in a system of cold atoms in optical microtraps is analyzed. The dynamics of two spin qubits is simulated, and a number of processes that limit the efficiency of entanglement based on the Rydberg blockade effect are considered. A geometry of two-photon excitation of Rydberg states of atoms is proposed that makes it possible to increase the robustness of the system to variations in a number of parameters and to reduce losses associated with the incoherent scattering of the driving field.
Arrays of identical neutral atoms trapped in optical tweezers are a promising candidate for use in quantum computing. These platforms are highly scalable to large numbers of qubits and neutral atoms boost several attractive features as long coherence times and the possibility to be entangled via strong dipole-dipole interactions by driving them to highly excited Rydberg states. \nThe Thesis work is developed inside the framework of the QRydDemo project, whose aim in the next few years is to realize a neutral atom quantum processor with several hundred qubits. The smallest building blocks for the quantum computer are one and two-qubit gates: to entangle two atoms in the quantum register, a controlled-phase (CZ) gate will be implemented by shining fine-tuned laser pulses onto them. In this work, after giving a theoretical description of the Hamiltonian of two neutral atoms in the quantum register, a numerical simulation of this system is exploited to reproduce the behavior of the two-qubit CZ gate. Realistic effects are taken into account as finite temperature, imperfect Rydberg blockade, or decay out of the Rydberg state. A protocol with constant pulses is analyzed and its optimal parameters are found through classical optimizers. Then, time-dependent pulses are introduced and the optimal pulses are found through the optimal control algorithm dCRAB in an open-loop optimization. For the experimental realization of the gate, this analysis is of pivotal importance to know in which aspect more effort has to be put to maximize the experimental precision of the operation and thus improving the performance of the whole device \n
Individually trapped neutral atoms are a promising candidate for use in quantum computing and simulation applications. They are highly scalable, have long coherence times and can be entangled via strong dipole-dipole interactions by driving to highly excited Rydberg states. However, the fidelity of single atom operations as well as two-atom entangling operations is limited by intrinsic sources of decoherence such as atomic motion, as well as technical sources of noise such as laser intensity fluctuations and phase/frequency fluctuations. We study the effect of these factors on single atom Rabi oscillations and two-atom Rydberg blockaded Rabi oscillations, using perturbation theory and numerical simulation. We develop a window function approach which helps us qualitatively understand the significance of the different spectral components of the noise as well as quantitatively understand the dependence of the Rabi oscillation fidelity on Rabi frequency. This allows us to predict the maximum experimentally achievable fidelities using independent measurements of experimental parameters such as noise spectra and atomic temperature. Turning to the question of near-term scalability of the experimental system, we prototype and test a method of generating a ’ladder’ configuration of optical tweezers utilizing two independent lasers. Our setup allows us to fully tune the geometry of the ladder, namely the separation between the two rows, the angle between them, and their relative position along the axis of the ladder. This pseudo-2D configuration enables us to reach larger system sizes in the near future and allows us to access beyond 1D physics.
We present a detailed analysis and design of a neutral atom quantum logic device based on atoms in optical traps interacting via dipole-dipole coupling of Rydberg states. The dominant physical mechanisms leading to decoherence and loss of fidelity are enumerated. Our results support the feasibility of performing single- and two-qubit gates at MHz rates with decoherence probability and fidelity errors at the level of ${10}^{\ensuremath{-}3}$ for each operation. Current limitations and possible approaches to further improvement of the device are discussed.