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A quantum-dot spin qubit with coherence limited by charge noise and fidelity higher than 99.9%
- Source :
- Nature Nanotechnology. 13:102-106
- Publication Year :
- 2017
- Publisher :
- Springer Science and Business Media LLC, 2017.
-
Abstract
- Recent advances towards spin-based quantum computation have been primarily fuelled by elaborate isolation from noise sources, such as surrounding nuclear spins and spin-electric susceptibility, to extend spin coherence. In the meanwhile, addressable single-spin and spin-spin manipulations in multiple-qubit systems will necessitate sizable spin-electric coupling. Given background charge fluctuation in nanostructures, however, its compatibility with enhanced coherence should be crucially questioned. Here we realise a single-electron spin qubit with isotopically-enriched phase coherence time (20 microseconds) and fast electrical control speed (up to 30 MHz) mediated by extrinsic spin-electric coupling. Using rapid spin rotations, we reveal that the free-evolution dephasing is caused by charge (instead of conventional magnetic) noise featured by a 1/f spectrum over seven decades of frequency. The qubit nevertheless exhibits superior performance with single-qubit gate fidelities exceeding 99.9% on average. Our work strongly suggests that designing artificial spin-electric coupling with account taken of charge noise is a promising route to large-scale spin-qubit systems having fault-tolerant controllability.
- Subjects :
- Physics
Spins
Dephasing
Biomedical Engineering
Bioengineering
02 engineering and technology
021001 nanoscience & nanotechnology
Condensed Matter Physics
01 natural sciences
Atomic and Molecular Physics, and Optics
Controllability
Microsecond
Quantum dot
Quantum mechanics
Qubit
0103 physical sciences
Condensed Matter::Strongly Correlated Electrons
General Materials Science
Electrical and Electronic Engineering
010306 general physics
0210 nano-technology
Quantum computer
Coherence (physics)
Subjects
Details
- ISSN :
- 17483395 and 17483387
- Volume :
- 13
- Database :
- OpenAIRE
- Journal :
- Nature Nanotechnology
- Accession number :
- edsair.doi.dedup.....d64289aa115686a024bd870695ef417f