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:quant-ph/0406117 · Physical Review A

Quantum computing with magnetically interacting atoms

Andrei Derevianko, Caleb C. Cannon

Published Dec 28, 2004• 38 citations
arXivHTMLPDF

Abstract

We propose a scalable quantum-computing architecture based on cold atoms confined to sites of a tight optical lattice. The lattice is placed in a nonuniform magnetic field and the resulting Zeeman sublevels define qubit states. Microwave pulses tuned to space-dependent resonant frequencies are used for individual addressing. The atoms interact via magnetic-dipole interactions allowing implementation of a universal controlled-NOT gate. The resulting gate operation times for alkalis-metals are on the order of milliseconds, much faster then the anticipated decoherence times. Single qubit operations take about $10\phantom{\rule{0.3em}{0ex}}\mathrm{\ensuremath{\mu}s}$. Analysis of motional decoherence due to NOT operations is given. We also comment on the improved feasibility of the proposed architecture with complex open-shell atoms, such as Cr, Eu, and metastable alkaline-earth atoms with larger magnetic moments.

DOI
10.1103/physreva.70.062319

Related papers

Quantum computing with magnetic atoms in optical lattices of reduced periodicity

Boris Ravaine, Andrei Derevianko, P. R. Berman

We investigate the feasibility of combining Raman optical lattices with a quantum computing architecture based on lattice-confined magnetically interacting neutral atoms. A particular advantage of the standing Raman field lattices comes from reduced interatomic separations leading to increased interatomic interactions and improved multiqubit gate performance. Specifically, we analyze a $J=3∕2$ Zeeman system placed in ${\ensuremath{\sigma}}_{+}\text{\ensuremath{-}}{\ensuremath{\sigma}}_{\ensuremath{-}}$ Raman fields which exhibit $\ensuremath{\lambda}∕4$ periodicity. We find that the resulting controlled-NOT (CNOT) gate operations times are in the order of millisecond. We also investigate motional and magnetic-field induced decoherences specific to the proposed architecture.

arXiv:quant-ph/0606162•Physical Review A•Aug 29, 2006•4 citations

Scalable Neutral Atom Quantum Computer with Interaction on Demand: Proposal for Selective Application of Two-Qubit Gate

Elham Hosseini Lapasar, Kenichi Kasamatsu, Yasushi Kondo +2 more

We propose a scalable neutral atom quantum computer with an on-demand interaction through a selective two-qubit gate operation. Atoms are trapped by a lattice of near field Fresnel diffraction lights so that each trap captures a single atom. One-qubit gate operation is implemented by a gate control laser beam which is applied to an individual atom. Two-qubit gate operation between an arbitrary pair of atoms is implemented by sending these atoms to a state-dependent optical lattice and making them collide so that a particular two-qubit state acquires a dynamical phase. We give numerical evaluations corresponding to these processes, from which we estimate the upper bound of a two-qubit gate operation time and corresponding gate fidelity. Our proposal is feasible within currently available technology developed in cold atom gas, MEMS, nanolithography, and various areas in optics.

arXiv:1101.4300•Journal of the Physical Society of Japan•Oct 28, 2011•6 citations

Quantum computation with ultracold atoms in a driven optical lattice

Philipp‐Immanuel Schneider, Alejandro Sáenz

We propose a scheme for quantum computation in optical lattices. The qubits are encoded in the spatial wave function of the atoms such that spin decoherence does not influence the computation. Quantum operations are steered by shaking the lattice, while qubit addressability can be provided with experimentally available techniques of changing the lattice with single-site resolution. Numerical calculations show possible fidelities above 99$%$ with gate times on the order of milliseconds.

arXiv:1103.4950•Physical Review A•May 16, 2012•34 citations

Quantum computation architecture using optical tweezers

Christof Weitenberg, Stefan Kuhr, Klaus Mølmer +1 more

We present a complete architecture for scalable quantum computation with ultracold atoms in optical lattices using optical tweezers focused to the size of a lattice spacing. We discuss three different two-qubit gates based on local collisional interactions. The gates between arbitrary qubits require the transport of atoms to neighboring sites. We numerically optimize the nonadiabatic transport of the atoms through the lattice and the intensity ramps of the optical tweezer in order to maximize the gate fidelities. We find overall gate times of a few $100\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}$s, while keeping the error probability due to vibrational excitations and spontaneous scattering below ${10}^{\ensuremath{-}3}$. The requirements on the positioning error and intensity noise of the optical tweezer and the magnetic field stability are analyzed and we show that atoms in optical lattices could meet the requirements for fault-tolerant scalable quantum computing.

arXiv:1107.2632•Physical Review A•Sep 16, 2011•67 citations

Control of neutral atoms in optical lattices

Brian Mischuck

Neutral atoms are promising candidates to store and manipulate quantum information. In this thesis we examine several problems related to the control of neutral atoms for quantum computation and simulation. In the first problem we show how the transport of atoms in an optical lattice can be controlled through variation of the polarization of the optical lattice and the application of global microwave pulses. This type of control control is a first step in many of the schemes for quantum computation and quantum simulation. We show that with the available tools for global control, the synthesis of any unitary transformation, consistent with translational invariance, may be performed and provide an explicit method for carrying this out. In the second problem, we study a spectroscopic method for probing atomic interactions that may form the basis for two-qudit quantum logic gates. The confinement of atoms required to perform quantum computation can strongly affect how they interact. Probing the nature of those confinement-induced effects is a first step towards quantum computing with neutral atoms. Transport of the atoms to overlapping wells is achieved through microwave pulses that drive population between hyperfine levels in a lin-perp-lin polarization-gradient lattice. By measuring the amount of population transferred into certain excited states, we can detect changes in the spectrum of the two-atom system induced by the interaction. In the third problem, we consider a cloud of cold atoms driven by both microwave and radio-frequency magnetic fields. The large number of spin sublevels available in individual atoms makes them candidates for a qudit-based quantum computer. Because the applied fields that drive the system may be inhomogeneous, the collection of atoms forms an ensemble of different qudits. Borrowing ideas developed for NMR control, we show how to drive the ensemble through a given evolution. We show that even in the presence of large experimental errors, state preparation may be achieved with high fidelities. We also show that intentionally applied variations in spatial magnetic fields can be used to synthesize different states in different regions of space.

•Sep 3, 2010•1 citation

Scalable Neutral Atom Quantum Computer with Interaction on Demand

Mikio Nakahara, Tetsuo Ohmi, Yasushi Kondo

We propose a scalable neutral atom quantum computer with an on-demand interaction. Artificial lattice of near field optical traps is employed to trap atom qubits. Interactions between atoms can be turned off if the atoms are separated by a high enough potential barrier so that the size of the atomic wave function is much less than the interatomic distance. One-qubit gate operation is implemented by a gate control laser beam which is attached to an individual atom. Two-qubit gate operation between a particular pair of atoms is introduced by leaving these atoms in an optical lattice and making them collide so that a particular two-qubit state acquires a dynamical phase. Our proposal is feasible within existing technology developed in cold atom gas, MEMS, nanolithography, and various areas in optics.

arXiv:1009.4426•Sep 22, 2010•0 citations
We propose a scalable quantum-computing architecture based on cold atoms confined to sites of a tight optical lattice. The lattice is placed in a nonuniform magnetic field and the resulting Zeeman sublevels define qubit states. Microwave pulses tuned to space-dependent resonant frequencies are used for individual addressing. The atoms interact via magnetic-dipole interactions allowing implementation of a universal controlled-NOT gate. The resulting gate operation times for alkalis-metals are on the order of milliseconds, much faster then the anticipated decoherence times. Single qubit operations take about 10\ensuremathμs10\phantom{\rule{0.3em}{0ex}}\mathrm{\ensuremath{\mu}s}10\ensuremathμs. Analysis of motional decoherence due to NOT operations is given. We also comment on the improved feasibility of the proposed architecture with complex open-shell atoms, such as Cr, Eu, and metastable alkaline-earth atoms with larger magnetic moments.
We investigate the feasibility of combining Raman optical lattices with a quantum computing architecture based on lattice-confined magnetically interacting neutral atoms. A particular advantage of the standing Raman field lattices comes from reduced interatomic separations leading to increased interatomic interactions and improved multiqubit gate performance. Specifically, we analyze a J=3∕2J=3∕2J=3∕2 Zeeman system placed in ${\ensuremath{\sigma}}_{+}\text{\ensuremath{-}}{\ensuremath{\sigma}}_{\ensuremath{-}}$ Raman fields which exhibit $\ensuremath{\lambda}∕4$ periodicity. We find that the resulting controlled-NOT (CNOT) gate operations times are in the order of millisecond. We also investigate motional and magnetic-field induced decoherences specific to the proposed architecture.
We propose a scalable neutral atom quantum computer with an on-demand interaction through a selective two-qubit gate operation. Atoms are trapped by a lattice of near field Fresnel diffraction lights so that each trap captures a single atom. One-qubit gate operation is implemented by a gate control laser beam which is applied to an individual atom. Two-qubit gate operation between an arbitrary pair of atoms is implemented by sending these atoms to a state-dependent optical lattice and making them collide so that a particular two-qubit state acquires a dynamical phase. We give numerical evaluations corresponding to these processes, from which we estimate the upper bound of a two-qubit gate operation time and corresponding gate fidelity. Our proposal is feasible within currently available technology developed in cold atom gas, MEMS, nanolithography, and various areas in optics.
We propose a scheme for quantum computation in optical lattices. The qubits are encoded in the spatial wave function of the atoms such that spin decoherence does not influence the computation. Quantum operations are steered by shaking the lattice, while qubit addressability can be provided with experimentally available techniques of changing the lattice with single-site resolution. Numerical calculations show possible fidelities above 99% with gate times on the order of milliseconds.
We present a complete architecture for scalable quantum computation with ultracold atoms in optical lattices using optical tweezers focused to the size of a lattice spacing. We discuss three different two-qubit gates based on local collisional interactions. The gates between arbitrary qubits require the transport of atoms to neighboring sites. We numerically optimize the nonadiabatic transport of the atoms through the lattice and the intensity ramps of the optical tweezer in order to maximize the gate fidelities. We find overall gate times of a few $100\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}$s, while keeping the error probability due to vibrational excitations and spontaneous scattering below ${10}^{\ensuremath{-}3}$. The requirements on the positioning error and intensity noise of the optical tweezer and the magnetic field stability are analyzed and we show that atoms in optical lattices could meet the requirements for fault-tolerant scalable quantum computing.
Neutral atoms are promising candidates to store and manipulate quantum information. In this thesis we examine several problems related to the control of neutral atoms for quantum computation and simulation. In the first problem we show how the transport of atoms in an optical lattice can be controlled through variation of the polarization of the optical lattice and the application of global microwave pulses. This type of control control is a first step in many of the schemes for quantum computation and quantum simulation. We show that with the available tools for global control, the synthesis of any unitary transformation, consistent with translational invariance, may be performed and provide an explicit method for carrying this out. In the second problem, we study a spectroscopic method for probing atomic interactions that may form the basis for two-qudit quantum logic gates. The confinement of atoms required to perform quantum computation can strongly affect how they interact. Probing the nature of those confinement-induced effects is a first step towards quantum computing with neutral atoms. Transport of the atoms to overlapping wells is achieved through microwave pulses that drive population between hyperfine levels in a lin-perp-lin polarization-gradient lattice. By measuring the amount of population transferred into certain excited states, we can detect changes in the spectrum of the two-atom system induced by the interaction. In the third problem, we consider a cloud of cold atoms driven by both microwave and radio-frequency magnetic fields. The large number of spin sublevels available in individual atoms makes them candidates for a qudit-based quantum computer. Because the applied fields that drive the system may be inhomogeneous, the collection of atoms forms an ensemble of different qudits. Borrowing ideas developed for NMR control, we show how to drive the ensemble through a given evolution. We show that even in the presence of large experimental errors, state preparation may be achieved with high fidelities. We also show that intentionally applied variations in spatial magnetic fields can be used to synthesize different states in different regions of space.
We propose a scalable neutral atom quantum computer with an on-demand interaction. Artificial lattice of near field optical traps is employed to trap atom qubits. Interactions between atoms can be turned off if the atoms are separated by a high enough potential barrier so that the size of the atomic wave function is much less than the interatomic distance. One-qubit gate operation is implemented by a gate control laser beam which is attached to an individual atom. Two-qubit gate operation between a particular pair of atoms is introduced by leaving these atoms in an optical lattice and making them collide so that a particular two-qubit state acquires a dynamical phase. Our proposal is feasible within existing technology developed in cold atom gas, MEMS, nanolithography, and various areas in optics.