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.

Demonstration of interferometer enhancement through Einstein–Podolsky–Rosen entanglement

Abstract

The recent series of gravitational-wave detections by the Advanced LIGO and Advanced Virgo observatories have launched the new field of gravitational-wave astronomy. As the sensitivity of gravitational-wave detectors is limited by the quantum noise of light, concepts from quantum metrology have been adapted to increase the observational range. Since 2010, squeezed light with reduced quantum noise has been used to achieve improved sensitivity at signal frequencies above 100 Hz. However, 100-m-long optical filter resonators would be required to also improve the sensitivity at lower frequencies, adding significant cost and complexity. Here, we report a proof-of-principle set-up of an alternative concept that achieves the broadband noise reduction by using Einstein–Podolsky–Rosen entangled states instead. We show that the desired sensitivity improvement can then be obtained with the signal recycling resonator that is already part of current observatories, providing a viable alternative to high-cost filter cavities.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Fig. 1: Simulation of the improvement in readout quantum noise of a typical laser interferometer with squeezed light for gravitational-wave detection.
Fig. 2: Simplified representation of this work’s experimental set-up.
Fig. 3: Schematics showing the relative positions of signal and idler bands around ωI and ωS and demonstration of frequency-dependent squeeze angle rotation.
Fig. 4: Results of an additional experimental step demonstrating the flexibility of the set-up.

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.

References

  1. 1.

    Abernathy, M. et al. Einstein Gravitational Wave Telescope Conceptual Design Study Technical Report ET-0106C-10 (European Gravitational Observatory, 2011); https://tds.virgo-gw.eu/?call_file=ET-0106C-10.pdf

  2. 2.

    Lantz, B. et al. Instrument Science White Paper 2018 Technical Note LIGO-T1800133-v3 (LIGO Document Control Center, 2018); https://dcc.ligo.org/LIGO-T1800133/public

  3. 3.

    Abbott, B. P. et al. Exploring the sensitivity of next generation gravitational wave detectors. Classical Quantum Gravity 34, 044001 (2017).

    ADS  Article  Google Scholar 

  4. 4.

    Chan, M. L., Messenger, C., Heng, I. S. & Hendry, M. Binary neutron star mergers and third generation detectors: localization and early warning. Phys. Rev. D 97, 123014 (2018).

    ADS  Article  Google Scholar 

  5. 5.

    LIGO Scientific Collaboration and Virgo Collaboration. GW170817: observation of gravitational waves from a binary neutron star inspiral. Phys. Rev. Lett. 119, 161101 (2017).

  6. 6.

    Walls, D. F. Squeezed states of light. Nature 306, 141–146 (1983).

    ADS  Article  Google Scholar 

  7. 7.

    Breitenbach, G., Schiller, S. & Mlynek, J. Measurement of the quantum states of squeezed light. Nature 387, 471–475 (1997).

    ADS  Article  Google Scholar 

  8. 8.

    Schnabel, R. Squeezed states of light and their applications in laser interferometers. Phys. Rep. 684, 1–51 (2017).

    ADS  MathSciNet  Article  Google Scholar 

  9. 9.

    Caves, C. M. Quantum-mechanical noise in an interferometer. Phys. Rev. D 23, 1693–1708 (1981).

    ADS  Article  Google Scholar 

  10. 10.

    Schnabel, R., Mavalvala, N., McClelland, D. E. & Lam, P. K. Quantum metrology for gravitational wave astronomy. Nat. Commun. 1, 121 (2010).

    ADS  Article  Google Scholar 

  11. 11.

    McClelland, D. E., Mavalvala, N., Chen, Y. & Schnabel, R. Advanced interferometry, quantum optics and optomechanics in gravitational wave detectors. Laser Photon. Rev. 5, 677–696 (2011).

    Google Scholar 

  12. 12.

    The LIGO Scientific Collaboration. A gravitational wave observatory operating beyond the quantum shot-noise limit. Nat. Phys. 7, 962–965 (2011).

  13. 13.

    The LIGO Scientific Collaboration. Enhanced sensitivity of the LIGO gravitational wave detector by using squeezed states of light. Nat. Photon. 7, 613–619 (2013).

  14. 14.

    Grote, H. et al. First long-term application of squeezed states of light in a gravitational-wave observatory. Phys. Rev. Lett. 110, 181101 (2013).

    ADS  Article  Google Scholar 

  15. 15.

    Jaekel, M. T. & Reynaud, S. Quantum limits in interferometric measurements. Europhys. Lett. 13, 301 (1990).

    ADS  Article  Google Scholar 

  16. 16.

    Danilishin, S. L. & Khalili, F. Y. Quantum measurement theory in gravitational-wave detectors. Rev. Relat. 15, 5–147 (2012).

    MATH  Google Scholar 

  17. 17.

    Kimble, H. J., Levin, Y., Matsko, A. B., Thorne, K. S. & Vyatchanin, S. P. Conversion of conventional gravitational-wave interferometers into quantum nondemolition interferometers by modifying their input and/or output optics. Phys. Rev. D 65, 022002 (2001).

    ADS  Article  Google Scholar 

  18. 18.

    Chelkowski, S. et al. Experimental characterization of frequency-dependent squeezed light. Phys. Rev. A 71, 013806 (2005).

    ADS  Article  Google Scholar 

  19. 19.

    Khalili, F. Y. Optimal configurations of filter cavity in future gravitational-wave detectors. Phys. Rev. D 81, 122002 (2010).

    ADS  Article  Google Scholar 

  20. 20.

    Barsotti, L., Harms, J. & Schnabel, R. Squeezed vacuum states of light for gravitational wave detectors. Rep. Prog. Phys. 82, 016905 (2018).

    ADS  Article  Google Scholar 

  21. 21.

    Ma, Y. et al. Proposal for gravitational-wave detection beyond the standard quantum limit through EPR entanglement. Nat. Phys. 13, 776–780 (2017).

    Article  Google Scholar 

  22. 22.

    Einstein, A., Podolsky, B. & Rosen, N. Can quantum-mechanical description of physical reality be considered complete? Phys. Rev. 47, 777–780 (1935).

    ADS  Article  Google Scholar 

  23. 23.

    Reid, M. D. Demonstration of the Einstein–Podolsky–Rosen paradox using nondegenerate parametric amplification. Phys. Rev. A 40, 913–923 (1989).

    ADS  Article  Google Scholar 

  24. 24.

    Bowen, W. P., Schnabel, R., Lam, P. K. & Ralph, T. C. Experimental characterization of continuous-variable entanglement. Phys. Rev. A 69, 012304 (2005).

    ADS  Article  Google Scholar 

  25. 25.

    Schori, C., Sørensen, J. L. & Polzik, E. S. Narrow-band frequency tunable light source of continuous quadrature entanglement. Phys. Rev. A 66, 033802 (2002).

    ADS  Article  Google Scholar 

  26. 26.

    Hage, B., Samblowski, A. & Schnabel, R. Towards Einstein–Podolsky–Rosen quantum channel multiplexing. Phys. Rev. A 81, 062301 (2010).

    ADS  MathSciNet  Article  Google Scholar 

  27. 27.

    Brown, D. D. et al. Broadband sensitivity enhancement of detuned dual-recycled michelson interferometers with EPR entanglement. Phys. Rev. D 96, 062003 (2017).

    ADS  Article  Google Scholar 

  28. 28.

    Marino, A. M., Stroud, C. R. Jr, Bennink, R. S. & Boyd, R. W. Bichromatic local oscillator for detection of two-mode squeezed states of light. J. Opt. Soc. Am. 24, 335–339 (2007).

    ADS  Article  Google Scholar 

  29. 29.

    Li, W., Jin, Y., Yu, X. & Zhang, J. Enhanced detection of a low-frequency signal by using broad squeezed light and a bichromatic local oscillator. Phys. Rev. A 96, 023808 (2017).

    ADS  Article  Google Scholar 

  30. 30.

    Beckey, J. L., Ma, Y., Boyer, V. & Miao, H. Broadband quantum noise reduction in future long baseline gravitational-wave detectors via EPR entanglement. Phys. Rev. D 100, 083011 (2019).

    ADS  Article  Google Scholar 

  31. 31.

    Yap, M. J. et al. Generation and control of frequency-dependent squeezing via Einstein–Podolsky–Rosen entanglement. Nat. Photon. https://doi.org/10.1038/s41566-019-0582-4 (2020).

Download references

Acknowledgements

This work was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation, SCHN 757/6-1), supported by the DFG under Germany’s Excellence Strategy EXC 2121 (‘Quantum Universe’, 390833306) and by the European Research Council (ERC) Project ‘MassQ’ (grant no. 339897).

Author information

Affiliations

Authors

Contributions

J.S., S.S. and R.S. planned the experiment. J.S. and S.S. built and performed the experiment. M.K. provided the theoretical analysis. All authors prepared the manuscript.

Corresponding author

Correspondence to Roman Schnabel.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Südbeck, J., Steinlechner, S., Korobko, M. et al. Demonstration of interferometer enhancement through Einstein–Podolsky–Rosen entanglement. Nat. Photonics 14, 240–244 (2020). https://doi.org/10.1038/s41566-019-0583-3

Download citation

Further reading

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