Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Spectroscopy of spontaneous spin noise as a probe of spin dynamics and magnetic resonance

Abstract

Not all noise in experimental measurements is unwelcome. Certain fundamental noise sources contain valuable information about the system itself—a notable example being the inherent voltage fluctuations (Johnson noise) that exist across any resistor, which allow the temperature to be determined1,2. In magnetic systems, fundamental noise can exist in the form of random spin fluctuations3,4. For example, statistical fluctuations of N paramagnetic spins should generate measurable noise of order √(N) spins, even in zero magnetic field5,6. Here we exploit this effect to perform perturbation-free magnetic resonance. We use off-resonant Faraday rotation to passively7,8 detect the magnetization noise in an equilibrium ensemble of paramagnetic alkali atoms; the random fluctuations generate spontaneous spin coherences that precess and decay with the same characteristic energy and timescales as the macroscopic magnetization of an intentionally polarized or driven ensemble. Correlation spectra of the measured spin noise reveal g-factors, nuclear spin, isotope abundance ratios, hyperfine splittings, nuclear moments and spin coherence lifetimes—without having to excite, optically pump or otherwise drive the system away from thermal equilibrium. These noise signatures scale inversely with interaction volume, suggesting a possible route towards non-perturbative, sourceless magnetic resonance of small systems.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: Spontaneous spin noise in Rb or K vapour, probed via Faraday rotation.
Figure 2: Total integrated spin noise from 85Rb as a function of laser detuning from the D1 (black points) and D2 (blue points) transitions.
Figure 3: Spin noise from 85Rb versus spin density and beam cross-section.
Figure 4: The ground-state Zeeman and hyperfine structure of 87Rb and 39K as revealed by stochastic spin coherences.

References

  1. Johnson, J. B. Thermal agitation of electricity in conductors. Nature 119, 50–51 (1927)

    Article  ADS  Google Scholar 

  2. White, D. R. et al. The status of Johnson noise thermometry. Metrologia 33, 325–335 (1996)

    Article  ADS  Google Scholar 

  3. Itano, W. M. et al. Quantum projection noise: Population fluctuations in two-level systems. Phys. Rev. A 47, 3554–3570 (1993)

    Article  ADS  CAS  Google Scholar 

  4. Sorensen, J. L., Hald, J. & Polzik, E. S. Quantum noise of an atomic spin polarization measurement. Phys. Rev. Lett. 80, 3487–3490 (1998)

    Article  ADS  CAS  Google Scholar 

  5. Bloch, F. Nuclear induction. Phys. Rev. 70, 460–474 (1946)

    Article  ADS  CAS  Google Scholar 

  6. Sleator, T., Hahn, E. L., Hilbert, C. & Clarke, J. Nuclear-spin noise. Phys. Rev. Lett. 55, 1742–1745 (1985)

    Article  ADS  CAS  Google Scholar 

  7. Happer, W. & Mathur, B. S. Off-resonant light as a probe of optically-pumped alkali vapors. Phys. Rev. Lett. 18, 577–580 (1967)

    Article  ADS  Google Scholar 

  8. Suter, D. & Mlynek, J. Laser excitation and detection of magnetic resonance. Adv. Magn. Opt. Res. 16, 1–83 (1991)

    Article  CAS  Google Scholar 

  9. Kubo, R. The fluctuation-dissipation theorem. Rep. Prog. Phys. 29, 255–284 (1966)

    Article  ADS  CAS  Google Scholar 

  10. Weissman, M. B. What is a spin glass? A glimpse via mesoscopic noise. Rev. Mod. Phys. 65, 829–839 (1993)

    Article  ADS  CAS  Google Scholar 

  11. Smith, N. & Arnett, P. White-noise magnetization fluctuations in magnetoresistive heads. Appl. Phys. Lett. 78, 1448–1450 (2001)

    Article  ADS  CAS  Google Scholar 

  12. Awschalom, D. D., DiVincenzo, D. P. & Smyth, J. F. Macroscopic quantum effects in nanometer-scale magnets. Science 258, 414–421 (1992)

    Article  ADS  CAS  Google Scholar 

  13. Aleksandrov, E. B. & Zapassky, V. S. Magnetic resonance in the Faraday-rotation noise spectrum. Zh. Eksp. Teor. Fiz. 81, 132–138 (1981)

    CAS  Google Scholar 

  14. Mitsui, T. Spontaneous noise spectroscopy of an atomic resonance. Phys. Rev. Lett. 84, 5292–5295 (2000)

    Article  ADS  CAS  Google Scholar 

  15. Kuzmich, A. et al. Quantum nondemolition measurements of collective atomic spin. Phys. Rev. A 60, 2346–2350 (1999)

    Article  ADS  CAS  Google Scholar 

  16. Kuzmich, A., Mandel, L. & Bigelow, N. P. Generation of spin squeezing via continuous quantum nondemolition measurement. Phys. Rev. Lett. 85, 1594–1597 (2000)

    Article  ADS  CAS  Google Scholar 

  17. Mamin, H. J., Budakian, R., Chui, B. W. & Rugar, D. Detection and manipulation of statistical polarization in small spin ensembles. Phys. Rev. Lett. 91, 207604 (2003)

    Article  ADS  CAS  Google Scholar 

  18. Manassen, Y., Hamers, R. J., Demuth, J. E. & Castellano, A. J. Direct observation of the precession of individual paramagnetic spins on oxidized silicon surfaces. Phys. Rev. Lett. 62, 2531–2534 (1989)

    Article  ADS  CAS  Google Scholar 

  19. Nussinov, Z., Crommie, M. F. & Balatsky, A. V. Noise spectroscopy of a single spin with spin-polarized STM. Phys. Rev. B 68, 085402 (2003)

    Article  ADS  Google Scholar 

  20. Cleland, A. N. & Roukes, M. L. Noise processes in nanomechanical resonators. J. Appl. Phys. 92, 2758–2769 (2002)

    Article  ADS  CAS  Google Scholar 

  21. Weaver, R. L. & Lobkis, O. I. Ultrasonics without a source: Thermal fluctuation correlations at MHz frequencies. Phys. Rev. Lett. 87, 134301 (2001)

    Article  ADS  CAS  Google Scholar 

  22. Kastler, A. Optical methods for studying Hertzian resonances. Science 158, 214–221 (1967)

    Article  ADS  CAS  Google Scholar 

  23. Happer, W. Optical pumping. Rev. Mod. Phys. 44, 169–249 (1972)

    Article  ADS  CAS  Google Scholar 

  24. Corney, A. Atomic and Laser Spectroscopy (Clarendon, Oxford, 1977)

    Google Scholar 

  25. Yabuzaki, T., Mitsui, T. & Tanaka, U. New type of high-resolution spectroscopy with a diode laser. Phys. Rev. Lett. 67, 2453–2456 (1991)

    Article  ADS  CAS  Google Scholar 

  26. Ito, T., Shimomura, N. & Yabuzaki, T. Noise spectroscopy of K atoms with a diode laser. J. Phys. Soc. Jpn 72, 962–963 (2003)

    Article  ADS  CAS  Google Scholar 

  27. Jury, J. C., Klaassen, K. B., van Peppen, J. & Wang, S. X. Measurement and analysis of noise sources in magnetoresistive sensors up to 6 GHz. IEEE Trans. Magn. 38, 3545–3555 (2002)

    Article  ADS  Google Scholar 

  28. Wolf, S. A. et al. Spintronics: A spin-based electronics vision for the future. Science 294, 1488–1495 (2001)

    Article  ADS  CAS  Google Scholar 

  29. Imamoglu, A. et al. Quantum information processing using quantum dot spins and cavity QED. Phys. Rev. Lett. 83, 4204–4207 (1999)

    Article  ADS  CAS  Google Scholar 

  30. Joglekar, Y. N., Balatsky, A. V. & MacDonald, A. H. Noise spectroscopy and interlayer phase coherence in bilayer quantum Hall systems. Phys. Rev. Lett. 92, 086803 (2004)

    Article  ADS  Google Scholar 

Download references

Acknowledgements

We thank P. Littlewood, S. Gider, P. Crowell and P. Crooker for discussions. This work was supported by the Los Alamos LDRD programme.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to S. A. Crooker.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Supplementary information

Supplementary Figure

An additional figure of spin noise data, this time from atoms having nuclear spin 5/2. (PDF 169 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Crooker, S., Rickel, D., Balatsky, A. et al. Spectroscopy of spontaneous spin noise as a probe of spin dynamics and magnetic resonance. Nature 431, 49–52 (2004). https://doi.org/10.1038/nature02804

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature02804

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing