The Experts below are selected from a list of 326469 Experts worldwide ranked by ideXlab platform
Vladan Vuletic - One of the best experts on this subject based on the ideXlab platform.
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parallel implementation of high fidelity multiqubit gates with neutral atoms
Physical Review Letters, 2019Co-Authors: Harry Levine, Alexander Keesling, Giulia Semeghini, Ahmed Omran, Tout T Wang, Sepehr Ebadi, Hannes Bernien, Markus Greiner, Vladan VuleticAbstract:We report the implementation of universal two- and three-qubit entangling gates on neutral-atom qubits encoded in long-lived hyperfine ground states. The gates are mediated by excitation to strongly interacting Rydberg states and are implemented in parallel on several clusters of atoms in a One-Dimensional Array of optical tweezers. Specifically, we realize the controlled-phase gate, enacted by a novel, fast protocol involving only global coupling of two qubits to Rydberg states. We benchmark this operation by preparing Bell states with fidelity F≥95.0(2)%, and extract gate fidelity ≥97.4(3)%, averaged across five atom pairs. In addition, we report a proof-of-principle implementation of the three-qubit Toffoli gate, in which two control atoms simultaneously constrain the behavior of one target atom. These experiments demonstrate key ingredients for high-fidelity quantum information processing in a scalable neutral-atom platform.
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one dimensional Array of ion chains coupled to an optical cavity
New Journal of Physics, 2013Co-Authors: Marko Cetina, Alexei Bylinskii, Leon Karpa, Dorian Gangloff, Kristin M Beck, Matthias Scholz, Andrew T Grier, Isaac L Chuang, Vladan VuleticAbstract:We present a novel system where an optical cavity is integrated with amicrofabricatedplanar-electrode iontrap.The trapelectrodesproduceatunable periodic potential allowing the trapping of up to 50 separate ion chains aligned with the cavity and spaced by 160µm in a One-Dimensional Array along the cavity axis. Each chain can contain up to 20 individually addressable Yb + ions coupled to the cavity mode. We demonstrate deterministic distribution of ions between the sites of the electrostatic periodic potential and control of the ion-cavity coupling. The measured strength of this coupling should allow access to the strong collective coupling regime with .10 ions. The optical cavity could serve as a quantum information bus between ions or be used to generate a strong wavelength-scale periodic optical potential.
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one dimensional Array of ion chains coupled to an optical cavity
arXiv: Quantum Physics, 2013Co-Authors: Marko Cetina, Alexei Bylinskii, Leon Karpa, Dorian Gangloff, Kristin M Beck, Matthias Scholz, Andrew T Grier, Isaac L Chuang, Vladan VuleticAbstract:We present a novel hybrid system where an optical cavity is integrated with a microfabricated planar-electrode ion trap. The trap electrodes produce a tunable periodic potential allowing the trapping of up to 50 separate ion chains spaced by 160 $\mu$m along the cavity axis. Each chain can contain up to 20 individually addressable Yb\textsuperscript{+} ions coupled to the cavity mode. We demonstrate deterministic distribution of ions between the sites of the electrostatic periodic potential and control of the ion-cavity coupling. The measured strength of this coupling should allow access to the strong collective coupling regime with $\lesssim$10 ions. The optical cavity could serve as a quantum information bus between ions or be used to generate a strong wavelength-scale periodic optical potential.
J R Petta - One of the best experts on this subject based on the ideXlab platform.
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shuttling a single charge across a one dimensional Array of silicon quantum dots
Nature Communications, 2019Co-Authors: Adam Mills, T. M. Hazard, D M Zajac, Michael Gullans, F J Schupp, J R PettaAbstract:Significant advances have been made towards fault-tolerant operation of silicon spin qubits, with single qubit fidelities exceeding 99.9%, several demonstrations of two-qubit gates based on exchange coupling, and the achievement of coherent single spin-photon coupling. Coupling arbitrary pairs of spatially separated qubits in a quantum register poses a significant challenge as most qubit systems are constrained to two dimensions with nearest neighbor connectivity. For spins in silicon, new methods for quantum state transfer should be developed to achieve connectivity beyond nearest-neighbor exchange. Here we demonstrate shuttling of a single electron across a linear Array of nine series-coupled silicon quantum dots in ~50 ns via a series of pairwise interdot charge transfers. By constructing more complex pulse sequences we perform parallel shuttling of two and three electrons at a time through the Array. These experiments demonstrate a scalable approach to physically transporting single electrons across large silicon quantum dot Arrays. As quantum computers grow in complexity the challenge of moving information between physically separated qubits becomes more pressing. Mills et al. demonstrate transfer of single electrons across an Array of nine silicon quantum dots three orders of magnitude faster than spin qubit decoherence times.
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shuttling a single charge across a one dimensional Array of silicon quantum dots
arXiv: Mesoscale and Nanoscale Physics, 2018Co-Authors: Adam Mills, T. M. Hazard, D M Zajac, Michael Gullans, F J Schupp, J R PettaAbstract:Significant advances have been made towards fault-tolerant operation of silicon spin qubits, with single qubit fidelities exceeding 99.9%, several demonstrations of two-qubit gates based on exchange coupling, and the achievement of coherent single spin-photon coupling. Coupling arbitrary pairs of spatially separated qubits in a quantum register poses a significant challenge as most qubit systems are constrained to two dimensions (2D) with nearest neighbor connectivity. For spins in silicon, new methods for quantum state transfer should be developed to achieve connectivity beyond nearest-neighbor exchange. Here we demonstrate shuttling of a single electron across a linear Array of 9 series-coupled Si quantum dots in ~50 ns via a series of pairwise interdot charge transfers. By progressively constructing more complex pulse sequences we perform parallel shuttling of 2 and 3 electrons at a time through the 9-dot Array. These experiments establish that physical transport of single electrons is feasible in large silicon quantum dot Arrays.
Adam Mills - One of the best experts on this subject based on the ideXlab platform.
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shuttling a single charge across a one dimensional Array of silicon quantum dots
Nature Communications, 2019Co-Authors: Adam Mills, T. M. Hazard, D M Zajac, Michael Gullans, F J Schupp, J R PettaAbstract:Significant advances have been made towards fault-tolerant operation of silicon spin qubits, with single qubit fidelities exceeding 99.9%, several demonstrations of two-qubit gates based on exchange coupling, and the achievement of coherent single spin-photon coupling. Coupling arbitrary pairs of spatially separated qubits in a quantum register poses a significant challenge as most qubit systems are constrained to two dimensions with nearest neighbor connectivity. For spins in silicon, new methods for quantum state transfer should be developed to achieve connectivity beyond nearest-neighbor exchange. Here we demonstrate shuttling of a single electron across a linear Array of nine series-coupled silicon quantum dots in ~50 ns via a series of pairwise interdot charge transfers. By constructing more complex pulse sequences we perform parallel shuttling of two and three electrons at a time through the Array. These experiments demonstrate a scalable approach to physically transporting single electrons across large silicon quantum dot Arrays. As quantum computers grow in complexity the challenge of moving information between physically separated qubits becomes more pressing. Mills et al. demonstrate transfer of single electrons across an Array of nine silicon quantum dots three orders of magnitude faster than spin qubit decoherence times.
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shuttling a single charge across a one dimensional Array of silicon quantum dots
arXiv: Mesoscale and Nanoscale Physics, 2018Co-Authors: Adam Mills, T. M. Hazard, D M Zajac, Michael Gullans, F J Schupp, J R PettaAbstract:Significant advances have been made towards fault-tolerant operation of silicon spin qubits, with single qubit fidelities exceeding 99.9%, several demonstrations of two-qubit gates based on exchange coupling, and the achievement of coherent single spin-photon coupling. Coupling arbitrary pairs of spatially separated qubits in a quantum register poses a significant challenge as most qubit systems are constrained to two dimensions (2D) with nearest neighbor connectivity. For spins in silicon, new methods for quantum state transfer should be developed to achieve connectivity beyond nearest-neighbor exchange. Here we demonstrate shuttling of a single electron across a linear Array of 9 series-coupled Si quantum dots in ~50 ns via a series of pairwise interdot charge transfers. By progressively constructing more complex pulse sequences we perform parallel shuttling of 2 and 3 electrons at a time through the 9-dot Array. These experiments establish that physical transport of single electrons is feasible in large silicon quantum dot Arrays.
Stefano Longhi - One of the best experts on this subject based on the ideXlab platform.
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chiral excitation and effective bandwidth enhancement in tilted waveguide lattices
Optics Letters, 2020Co-Authors: Stefano LonghiAbstract:Light escape from an optical waveguide side-coupled to a waveguide lattice provides a photonic analogue of the spontaneous emission process of an excited two-level atom in a One-Dimensional Array of cavities. According to the Fermi golden rule, the decay process is prevented when the atomic resonance frequency falls in a stop band of the lattice, while time-reversal symmetry ensures that the spontaneously emitted photon has equal probability to propagate in opposite directions of the Array. This scenario is drastically modified when the quantum emitter drifts along the lattice. In the waveguide optics analogue, the atomic drift is emulated by the introduction of a slight geometric tilt of the waveguide axis from the lattice axis. In this setting, light excitation in the Array is chiral, i.e., light propagates in a preferred direction of the lattice, and coupling is allowed even though the waveguide is far detuned from the tight-binding lattice band.
R L Pavelich - One of the best experts on this subject based on the ideXlab platform.
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the tight binding formulation of the kronig penney model
Scientific Reports, 2017Co-Authors: F Marsiglio, R L PavelichAbstract:Electronic band structure calculations are frequently parametrized in tight-binding form; the latter representation is then often used to study electron correlations. In this paper we provide a derivation of the tight-binding model that emerges from the exact solution of a particle bound in a periodic One-Dimensional Array of square well potentials. We derive the dispersion for such a model, and show that an effective next-nearest-neighbour hopping parameter is required for an accurate description. An electron-hole asymmetry is prevalent except in the extreme tight-binding limit, and emerges through a “next-nearest-neighbour” hopping term in the dispersion. We argue that this does not necessarily imply next-nearest-neighbour tunneling; this assertion is demonstrated by deriving the transition amplitudes for a two-state effective model that describes a double-well potential, which is a simplified precursor to the problem of a periodic Array of potential wells. A next-nearest-neighbour tunneling parameter is required for an accurate description even though there are no such neighbours.
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the tight binding formulation of the kronig penney model
arXiv: Other Condensed Matter, 2017Co-Authors: F Marsiglio, R L PavelichAbstract:We provide a derivation of the tight-binding model that emerges from a full consideration of a particle bound in a periodic One-Dimensional Array of square well potentials, separated by barriers of height $V_0$ and width $b$. We derive the dispersion for such a model, and show that an effective next-nearest-neighbor hopping parameter is required for an accurate description. An electron-hole asymmetry is prevalent except in the extreme tight-binding limit, and emerges through a "next-nearest neighbor" hopping term in the dispersion. We argue that this does not necessarily imply next-nearest-neighbor tunneling; this is done by deriving the transition amplitudes for a two-state effective model that describes a double-well potential, which is a simplified precursor to the problem of a periodic Array of potential wells.
