dorsal/arxiv
View SchemaBang-bang control of fullerene qubits using ultra-fast phase gates
| Authors | John J. L. Morton, Alexei M. Tyryshkin, Arzhang Ardavan, Simon C. Benjamin, Kyriakos Porfyrakis, S. A. Lyon, G. Andrew D. Briggs |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0601008 |
| URL | https://arxiv.org/abs/quant-ph/0601008 |
| DOI | 10.1038/nphys192 |
| Journal | Nature Physics 2, 40-43 (2006) |
Abstract
Quantum mechanics permits an entity, such as an atom, to exist in a superposition of multiple states simultaneously. Quantum information processing (QIP) harnesses this profound phenomenon to manipulate information in radically new ways. A fundamental challenge in all QIP technologies is the corruption of superposition in a quantum bit (qubit) through interaction with its environment. Quantum bang-bang control provides a solution by repeatedly applying `kicks' to a qubit, thus disrupting an environmental interaction. However, the speed and precision required for the kick operations has presented an obstacle to experimental realization. Here we demonstrate a phase gate of unprecedented speed on a nuclear spin qubit in a fullerene molecule (N@C60), and use it to bang-bang decouple the qubit from a strong environmental interaction. We can thus trap the qubit in closed cycles on the Bloch sphere, or lock it in a given state for an arbitrary period. Our procedure uses operations on a second qubit, an electron spin, in order to generate an arbitrary phase on the nuclear qubit. We anticipate the approach will be vital for QIP technologies, especially at the molecular scale where other strategies, such as electrode switching, are unfeasible.
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"abstract": "Quantum mechanics permits an entity, such as an atom, to exist in a\nsuperposition of multiple states simultaneously. Quantum information processing\n(QIP) harnesses this profound phenomenon to manipulate information in radically\nnew ways. A fundamental challenge in all QIP technologies is the corruption of\nsuperposition in a quantum bit (qubit) through interaction with its\nenvironment. Quantum bang-bang control provides a solution by repeatedly\napplying `kicks\u0027 to a qubit, thus disrupting an environmental interaction.\nHowever, the speed and precision required for the kick operations has presented\nan obstacle to experimental realization. Here we demonstrate a phase gate of\nunprecedented speed on a nuclear spin qubit in a fullerene molecule (N@C60),\nand use it to bang-bang decouple the qubit from a strong environmental\ninteraction. We can thus trap the qubit in closed cycles on the Bloch sphere,\nor lock it in a given state for an arbitrary period. Our procedure uses\noperations on a second qubit, an electron spin, in order to generate an\narbitrary phase on the nuclear qubit. We anticipate the approach will be vital\nfor QIP technologies, especially at the molecular scale where other strategies,\nsuch as electrode switching, are unfeasible.",
"arxiv_id": "quant-ph/0601008",
"authors": [
"John J. L. Morton",
"Alexei M. Tyryshkin",
"Arzhang Ardavan",
"Simon C. Benjamin",
"Kyriakos Porfyrakis",
"S. A. Lyon",
"G. Andrew D. Briggs"
],
"categories": [
"quant-ph"
],
"doi": "10.1038/nphys192",
"journal_ref": "Nature Physics 2, 40-43 (2006)",
"title": "Bang-bang control of fullerene qubits using ultra-fast phase gates",
"url": "https://arxiv.org/abs/quant-ph/0601008"
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