Continuous Faraday measurement of spin precession without light shifts

M Jasperse, M J Kewming, Prasanna Pakkiam, R P Anderson, L D Turner

Research output: Contribution to journalArticleResearchpeer-review

Abstract

We describe a dispersive Faraday optical probe of atomic spin which performs a weak measurement of spin projection of a quantum gas continuously for more than one second. To date, focusing bright far-off-resonance probes onto quantum gases has proved invasive due to strong scalar and vector light shifts exerting dipole and Stern-Gerlach forces. We show that tuning the probe near the magic-zero wavelength at 790 nm between the fine-structure doublet of Rb87 cancels the scalar light shift, and careful control of polarization eliminates the vector light shift. Faraday rotations due to each fine-structure line reinforce at this wavelength, enhancing the signal-to-noise ratio for a fixed rate of probe-induced decoherence. Using this minimally invasive spin probe, we perform microscale atomic magnetometry at high temporal resolution. Spectrogram analysis of the Larmor precession signal of a single spinor Bose-Einstein condensate measures a time-varying magnetic field strength with 1 μG accuracy every 5 ms; or, equivalently, makes more than 200 successive measurements each at 10pT/Hz sensitivity.

Original languageEnglish
Article number063402
Number of pages11
JournalPhysical Review A
Volume96
Issue number6
DOIs
Publication statusPublished - 1 Dec 2017

Cite this

Jasperse, M ; Kewming, M J ; Pakkiam, Prasanna ; Anderson, R P ; Turner, L D. / Continuous Faraday measurement of spin precession without light shifts. In: Physical Review A. 2017 ; Vol. 96, No. 6.
@article{caf5ee81156547839266788da95483da,
title = "Continuous Faraday measurement of spin precession without light shifts",
abstract = "We describe a dispersive Faraday optical probe of atomic spin which performs a weak measurement of spin projection of a quantum gas continuously for more than one second. To date, focusing bright far-off-resonance probes onto quantum gases has proved invasive due to strong scalar and vector light shifts exerting dipole and Stern-Gerlach forces. We show that tuning the probe near the magic-zero wavelength at 790 nm between the fine-structure doublet of Rb87 cancels the scalar light shift, and careful control of polarization eliminates the vector light shift. Faraday rotations due to each fine-structure line reinforce at this wavelength, enhancing the signal-to-noise ratio for a fixed rate of probe-induced decoherence. Using this minimally invasive spin probe, we perform microscale atomic magnetometry at high temporal resolution. Spectrogram analysis of the Larmor precession signal of a single spinor Bose-Einstein condensate measures a time-varying magnetic field strength with 1 μG accuracy every 5 ms; or, equivalently, makes more than 200 successive measurements each at 10pT/Hz sensitivity.",
author = "M Jasperse and Kewming, {M J} and Prasanna Pakkiam and Anderson, {R P} and Turner, {L D}",
year = "2017",
month = "12",
day = "1",
doi = "10.1103/PhysRevA.96.063402",
language = "English",
volume = "96",
journal = "Physical Review A",
issn = "2469-9926",
publisher = "American Physical Society",
number = "6",

}

Continuous Faraday measurement of spin precession without light shifts. / Jasperse, M; Kewming, M J; Pakkiam, Prasanna; Anderson, R P; Turner, L D.

In: Physical Review A, Vol. 96, No. 6, 063402, 01.12.2017.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Continuous Faraday measurement of spin precession without light shifts

AU - Jasperse, M

AU - Kewming, M J

AU - Pakkiam, Prasanna

AU - Anderson, R P

AU - Turner, L D

PY - 2017/12/1

Y1 - 2017/12/1

N2 - We describe a dispersive Faraday optical probe of atomic spin which performs a weak measurement of spin projection of a quantum gas continuously for more than one second. To date, focusing bright far-off-resonance probes onto quantum gases has proved invasive due to strong scalar and vector light shifts exerting dipole and Stern-Gerlach forces. We show that tuning the probe near the magic-zero wavelength at 790 nm between the fine-structure doublet of Rb87 cancels the scalar light shift, and careful control of polarization eliminates the vector light shift. Faraday rotations due to each fine-structure line reinforce at this wavelength, enhancing the signal-to-noise ratio for a fixed rate of probe-induced decoherence. Using this minimally invasive spin probe, we perform microscale atomic magnetometry at high temporal resolution. Spectrogram analysis of the Larmor precession signal of a single spinor Bose-Einstein condensate measures a time-varying magnetic field strength with 1 μG accuracy every 5 ms; or, equivalently, makes more than 200 successive measurements each at 10pT/Hz sensitivity.

AB - We describe a dispersive Faraday optical probe of atomic spin which performs a weak measurement of spin projection of a quantum gas continuously for more than one second. To date, focusing bright far-off-resonance probes onto quantum gases has proved invasive due to strong scalar and vector light shifts exerting dipole and Stern-Gerlach forces. We show that tuning the probe near the magic-zero wavelength at 790 nm between the fine-structure doublet of Rb87 cancels the scalar light shift, and careful control of polarization eliminates the vector light shift. Faraday rotations due to each fine-structure line reinforce at this wavelength, enhancing the signal-to-noise ratio for a fixed rate of probe-induced decoherence. Using this minimally invasive spin probe, we perform microscale atomic magnetometry at high temporal resolution. Spectrogram analysis of the Larmor precession signal of a single spinor Bose-Einstein condensate measures a time-varying magnetic field strength with 1 μG accuracy every 5 ms; or, equivalently, makes more than 200 successive measurements each at 10pT/Hz sensitivity.

UR - http://www.scopus.com/inward/record.url?scp=85038212349&partnerID=8YFLogxK

U2 - 10.1103/PhysRevA.96.063402

DO - 10.1103/PhysRevA.96.063402

M3 - Article

VL - 96

JO - Physical Review A

JF - Physical Review A

SN - 2469-9926

IS - 6

M1 - 063402

ER -