Fullerene-based electron-spin quantum computer
TL;DR: In this article, an alternative concept for a scalable spin quantum computer that combines aspects of other proposals with the advantageous features of endohedral fullerenes was proposed, where electron spins instead of nuclear spins are used and that the manipulation of fullerene molecules is fairly easy.
Abstract: We propose an alternative concept for a scalable spin quantum computer that combines aspects of other proposals with the advantageous features of endohedral fullerenes. The key advantages are that electron spins instead of nuclear spins are used and that the manipulation of fullerene molecules is fairly easy. Qubits are set and read out via pulsed electron-spin resonance. Addressing is provided by local magnetic fields or field gradients $(A$ gate). The qubit-qubit interaction is mediated by magnetic dipolar coupling and can be controlled via the direction of the magnetic field with respect to the distance vector of the qubits $(J$ gate). Molecular as well as solid-state architectures are discussed.
Citations
More filters
TL;DR: Hybrid quantum circuits combine two or more physical systems, with the goal of harnessing the advantages and strengths of the different systems in order to better explore new phenomena and potentially bring about novel quantum technologies as discussed by the authors.
Abstract: Hybrid quantum circuits combine two or more physical systems, with the goal of harnessing the advantages and strengths of the different systems in order to better explore new phenomena and potentially bring about novel quantum technologies. This article presents a brief overview of the progress achieved so far in the field of hybrid circuits involving atoms, spins, and solid-state devices (including superconducting and nanomechanical systems). How these circuits combine elements from atomic physics, quantum optics, condensed matter physics, and nanoscience is discussed, and different possible approaches for integrating various systems into a single circuit are presented. In particular, hybrid quantum circuits can be fabricated on a chip, facilitating their future scalability, which is crucial for building future quantum technologies, including quantum detectors, simulators, and computers.
1,439 citations
Cites background from "Fullerene-based electron-spin quant..."
...Group-V endohedral fullerenes, consisting of a groupV atom (e.g., nitrogen) trapped inside a fullerene cage, are another spin system (Harneit, 2002) that might be integrated in solid-state systems....
[...]
...Group-V (as nitrogen) endohedral fullerenes are another spin system (Harneit, 2002) that might be integrated in solid-state systems....
[...]
513 citations
TL;DR: In this paper, the transverse relaxation (decoherence) times of donor electron spins in phosphorus-doped silicon (Si:P) were shown to be over 2 orders of magnitude longer than previously demonstrated.
Abstract: Donor electron spins in phosphorus-doped silicon (Si:P) are a candidate two-level system (qubit) for quantum information processing. Spin echo measurements of isotopically purified ${}^{28}\mathrm{S}\mathrm{i}:\mathrm{P}$ are presented that show exceptionally long transverse relaxation (decoherence) times, ${T}_{2},$ at low temperature. Below $\ensuremath{\sim}10\mathrm{K}$ the spin decoherence is shown to be controlled by instantaneous diffusion and at higher temperatures by an Orbach process. ${T}_{2}$ for small pulse turning angles is 14 ms at 7 K and extrapolates to $\ensuremath{\sim}60\mathrm{ms}$ for an isolated spin, over 2 orders of magnitude longer than previously demonstrated.
391 citations
TL;DR: In this paper, a platform based on spin qubits connected through arrays of nanoelectromechanical resonators is proposed to reconcile the conflicting requirements of information leakage in a quantum computer.
Abstract: In a quantum computer, the data carriers (or qubits) must be well isolated from their environment to avoid information leakage. At the same time they have to interact with one another to process information. A proposed platform based on spin qubits connected through arrays of nanoelectromechanical resonators should be able to reconcile these conflicting requirements.
383 citations
TL;DR: An MRI technique that provides subnanometre spatial resolution in three dimensions, with single electron-spin sensitivity, is demonstrated and is immediately applicable to diverse systems including imaging spin chains, readout of spin-based quantum bits, and determining the location of spin labels in biological systems.
Abstract: Magnetic resonance imaging (MRI) has revolutionized biomedical science by providing non-invasive, three-dimensional biological imaging. However, spatial resolution in conventional MRI systems is limited to tens of micrometres, which is insufficient for imaging on molecular scales. Here, we demonstrate an MRI technique that provides subnanometre spatial resolution in three dimensions, with single electron-spin sensitivity. Our imaging method works under ambient conditions and can measure ubiquitous 'dark' spins, which constitute nearly all spin targets of interest. In this technique, the magnetic quantum-projection noise of dark spins is measured using a single nitrogen-vacancy (NV) magnetometer located near the surface of a diamond chip. The distribution of spins surrounding the NV magnetometer is imaged with a scanning magnetic-field gradient. To evaluate the performance of the NV-MRI technique, we image the three-dimensional landscape of electronic spins at the diamond surface and achieve an unprecedented combination of resolution (0.8 nm laterally and 1.5 nm vertically) and single-spin sensitivity. Our measurements uncover electronic spins on the diamond surface that can potentially be used as resources for improved magnetic imaging. This NV-MRI technique is immediately applicable to diverse systems including imaging spin chains, readout of spin-based quantum bits, and determining the location of spin labels in biological systems.
272 citations