dorsal/arxiv
View SchemaObservation of Faraday rotation from a single confined spin
| Authors | Mete Atature, Jan Dreiser, Antonio Badolato, Atac Imamoglu |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0610110 |
| URL | https://arxiv.org/abs/quant-ph/0610110 |
| DOI | 10.1038/nphys521 |
Abstract
Ability to read-out the state of a single confined spin lies at the heart of solid-state quantum information processing. While all-optical spin measurements using Faraday rotation has been successfully implemented in ensembles of semiconductor spins, read-out of a single semiconductor spin has only been achieved using transport measurements based on spin-charge conversion. Here, we demonstrate an all-optical dispersive measurement of the spin-state of a single electron trapped in a semiconductor quantum dot. We obtain information on the spin state through conditional Faraday rotation of a spectrally detuned optical field, induced by the polarization- and spin-selective trion (charged quantum dot) transitions. To assess the sensitivity of the technique, we use an independent resonant laser for spin-state preparation. An all-optical dispersive measurement on single spins has the important advantage of channeling the measurement back-action onto a conjugate observable, thereby allowing for repetitive or continuous quantum nondemolition (QND) read-out of the spin-state. We infer from our results that there are of order unity back-action induced spin-flip Raman scattering events within our measurement timescale. Therefore, straightforward improvements such as the use of a solid-immersion lens and higher efficiency detectors would allow for back-action evading spin measurements, without the need for a cavity.
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"abstract": "Ability to read-out the state of a single confined spin lies at the heart of\nsolid-state quantum information processing. While all-optical spin measurements\nusing Faraday rotation has been successfully implemented in ensembles of\nsemiconductor spins, read-out of a single semiconductor spin has only been\nachieved using transport measurements based on spin-charge conversion. Here, we\ndemonstrate an all-optical dispersive measurement of the spin-state of a single\nelectron trapped in a semiconductor quantum dot. We obtain information on the\nspin state through conditional Faraday rotation of a spectrally detuned optical\nfield, induced by the polarization- and spin-selective trion (charged quantum\ndot) transitions. To assess the sensitivity of the technique, we use an\nindependent resonant laser for spin-state preparation. An all-optical\ndispersive measurement on single spins has the important advantage of\nchanneling the measurement back-action onto a conjugate observable, thereby\nallowing for repetitive or continuous quantum nondemolition (QND) read-out of\nthe spin-state. We infer from our results that there are of order unity\nback-action induced spin-flip Raman scattering events within our measurement\ntimescale. Therefore, straightforward improvements such as the use of a\nsolid-immersion lens and higher efficiency detectors would allow for\nback-action evading spin measurements, without the need for a cavity.",
"arxiv_id": "quant-ph/0610110",
"authors": [
"Mete Atature",
"Jan Dreiser",
"Antonio Badolato",
"Atac Imamoglu"
],
"categories": [
"quant-ph"
],
"doi": "10.1038/nphys521",
"title": "Observation of Faraday rotation from a single confined spin",
"url": "https://arxiv.org/abs/quant-ph/0610110"
},
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