Single-spin qubits in isotopically enriched silicon at low magnetic field
| Autor: | Thaddeus D. Ladd, Bas Hensen, Kohei M. Itoh, Kuan Yen Tan, Andrey A. Kiselev, Tuomo Tanttu, Andrea Morello, Kok Wai Chan, Andrew S. Dzurak, Fay E. Hudson, Chih Hwan Yang, R. C. C. Leon, Will Gilbert, Ruichen Zhao, J. C. C. Hwang, Arne Laucht |
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| Přispěvatelé: | University of New South Wales, Quantum Computing and Devices, Keio University, HRL Laboratories, Department of Applied Physics, Aalto-yliopisto, Aalto University |
| Rok vydání: | 2019 |
| Předmět: |
Quantum information
Silicon Science FOS: Physical sciences General Physics and Astronomy chemistry.chemical_element 02 engineering and technology Electron 01 natural sciences Article General Biochemistry Genetics and Molecular Biology Quantum state Mesoscale and Nanoscale Physics (cond-mat.mes-hall) 0103 physical sciences lcsh:Science 010306 general physics Quantum computer Physics Multidisciplinary Condensed Matter - Mesoscale and Nanoscale Physics General Chemistry 021001 nanoscience & nanotechnology Magnetic field chemistry Quantum dot Qubit lcsh:Q Condensed Matter::Strongly Correlated Electrons Atomic physics 0210 nano-technology Qubits Coherence (physics) |
| Zdroj: | Nature Communications, Vol 10, Iss 1, Pp 1-9 (2019) Nature Communications |
| ISSN: | 2041-1723 |
| Popis: | Single-electron spin qubits employ magnetic fields on the order of 1 Tesla or above to enable quantum state readout via spin-dependent-tunnelling. This requires demanding microwave engineering for coherent spin resonance control, which limits the prospects for large scale multi-qubit systems. Alternatively, singlet-triplet readout enables high-fidelity spin-state measurements in much lower magnetic fields, without the need for reservoirs. Here, we demonstrate low-field operation of metal-oxide-silicon quantum dot qubits by combining coherent single-spin control with high-fidelity, single-shot, Pauli-spin-blockade-based ST readout. We discover that the qubits decohere faster at low magnetic fields with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${T}_{2}^{\,\text{Rabi}\,}=18.6$$\end{document}T2Rabi=18.6 μs and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${T}_{2}^{* }=1.4$$\end{document}T2*=1.4 μs at 150 mT. Their coherence is limited by spin flips of residual 29Si nuclei in the isotopically enriched 28Si host material, which occur more frequently at lower fields. Our finding indicates that new trade-offs will be required to ensure the frequency stabilization of spin qubits, and highlights the importance of isotopic enrichment of device substrates for the realization of a scalable silicon-based quantum processor. One of the main sources of decoherence in silicon electron spin qubits is their interaction with nearby fluctuating nuclear spins. Zhao et al. present a device made from enriched silicon to reduce the nuclear spin density and find its performance is still limited by fluctuations of residual spins. |
| Databáze: | OpenAIRE |
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