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Experimental realization of long-distance entanglement between spins in antiferromagnetic quantum spin chains

Abstract

Entanglement is a concept that has defied common sense since the discovery of quantum mechanics. Two particles are said to be entangled when the quantum state of each particle cannot be described independently, no matter how far apart in space and time the two particles are. We demonstrate experimentally that unpaired spins separated by several hundred ångström entangle through a collection of spin singlets made up of antiferromagnetic spin-1/2 chains in a bulk material. Low-temperature magnetization and specific heat studies as a function of magnetic field reveal the occurrence of very dilute spin dimers and at least two quantum phase transitions related to the breaking of excited local triplets. The mechanism at the origin of the unpaired spins inside the quantum chains is the inter-modulation potential between two sublattices, and may be replicated using well-designed synthetic multilayers.

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Figure 1: Sketch of a quantum communication channel and properties of spins entangled through antiferromagnetic interactions.
Figure 2: Detailed description of the structure and magnetic properties of the chain subsystem.
Figure 3: Magnetization data at low temperature and under magnetic fields.
Figure 4: Low-temperature specific heat experiments at different applied magnetic fields.
Figure 5: Quantum correlations.

References

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

    Article  ADS  Google Scholar 

  2. Nielsen, M. A. & Chuang, I. L. Quantum Computation and Quantum Information (Cambridge Univ. Press, 2000).

    MATH  Google Scholar 

  3. Amico, L., Fazio, R., Osterloh, A. & Vedral, V. Entanglement in many-body systems. Rev. Mod. Phys. 80, 517–576 (2008).

    Article  ADS  MathSciNet  Google Scholar 

  4. Braunstein, S. L. & van Loock, P. Quantum information with continuous variables. Rev. Mod. Phys. 77, 513–577 (2005).

    Article  ADS  MathSciNet  Google Scholar 

  5. Bose, S. Quantum communication through an unmodulated spin chain. Phys. Rev. Lett. 91, 207901 (2003).

    Article  ADS  Google Scholar 

  6. Bose, S. Quantum communication through spin chain dynamics: An introductory overview. Contemp. Phys. 48, 13–30 (2007).

    Article  ADS  Google Scholar 

  7. Campos Venuti, L., Degli Esposti Boschi, C. & Roncaglia, M. Long-distance entanglement in spin systems. Phys. Rev. Lett. 96, 247206 (2006).

    Article  ADS  Google Scholar 

  8. Campos Venuti, L., Degli Esposti Boschi, C. & Roncaglia, M. Qubit teleportation and transfer across antiferromagnetic spin chains. Phys. Rev. Lett. 99, 060401 (2007).

    Article  ADS  Google Scholar 

  9. Sodano, P., Bayat, A. & Bose, S. Kondo cloud mediated long-range entanglement after local quench in a spin chain. Phys. Rev. B 81, 100412 (2010).

    Article  ADS  Google Scholar 

  10. Bayat, A., Bose, S. & Sodano, P. Entanglement routers using macroscopic singlets. Phys. Rev. Lett. 105, 187204 (2010).

    Article  ADS  Google Scholar 

  11. Vuletic, T. et al. The spin-ladder and spin-chain system (La, Y, Sr, Ca)14Cu24O41: Electronic phases, charge and spin dynamics. Phys. Rep. 428, 169–258 (2006).

    Article  ADS  Google Scholar 

  12. Gellé, A. & Lepetit, M-B. Influence of the incommensurability in Sr14−xCaxCu24O41 family compounds. Phys. Rev. Lett. 92, 236402 (2004).

    Article  ADS  Google Scholar 

  13. Matsuda, M., Yosihama, T., Kakurai, K. & Shirane, G. Quasi-two-dimensional hole ordering and dimerized state in the CuO2-chain layers in Sr14Cu24O41 . Phys. Rev. B 59, 1060–1067 (1999).

    Article  ADS  Google Scholar 

  14. Regnault, L. P. et al. Spin dynamics in the magnetic chain arrays of Sr14Cu24O41: A neutron inelastic scattering investigation. Phys. Rev. B 59, 1055–1059 (1999).

    Article  ADS  Google Scholar 

  15. Klingeler, R. et al. Magnetization of hole-doped CuO2 spin chains in Sr14−xCaxCu24O41 . Phys. Rev. B 72, 184406 (2005).

    Article  ADS  Google Scholar 

  16. Fisher, Daniel S. Random antiferromagnetic quantum spin chains. Phys. Rev. B 50, 3799–3821 (1994).

    Article  ADS  Google Scholar 

  17. Wiesniak, M., Vedral, V. & Brukner, C. Magnetic susceptibility as a macroscopic entanglement witness. New J. Phys. 7, 258 (2005).

    Article  ADS  Google Scholar 

  18. Brukner, C., Vedral, V. & Zeilinger, A. Crucial role of quantum entanglement in bulk properties of solids. Phys. Rev. A 73, 012110 (2006).

    Article  ADS  Google Scholar 

  19. Chakraborty, T., Singh, H., Singh, S., Gopal, R. K. & Mitra, C. Probing quantum discord in a Heisenberg dimer compound. J. Phys. Condens. Matter 25, 425601 (2013).

    Article  Google Scholar 

  20. Chakraborty, T. et al. Experimental detection of thermal entanglement in a molecular chain. J. Appl. Phys. 114, 144904 (2013).

    Article  ADS  Google Scholar 

  21. Das, D., Singh, H., Chakraborty, T., Gopal, R. K. & Mitra, C. Experimental detection of quantum information sharing and its quantification in quantum spin systems. New J. Phys. 15, 013047 (2013).

    Article  ADS  Google Scholar 

  22. Wiesniak, M., Vedral, V. & Brukner, C. Heat capacity as an indicator of entanglement. Phys. Rev. B 78, 064108 (2008).

    Article  ADS  Google Scholar 

  23. Singh, H. et al. Experimental quantification of entanglement through heat capacity. New J. Phys. 15, 113001 (2013).

    Article  ADS  Google Scholar 

  24. Chakraborty, T., Singh, H. & Mitra, C. Signature of quantum entanglement in NH4CuPO4 H2O. J. Appl. Phys. 115, 034909 (2014).

    Article  ADS  Google Scholar 

  25. Arnesen, M. C., Bose, S. & Vedral, V. Natural thermal and magnetic entanglement in the 1D Heisenberg model. Phys. Rev. Lett. 87, 017901 (2001).

    Article  ADS  Google Scholar 

  26. Osborne, Tobias J. & Nielsen, Michael A. Entanglement in a simple quantum phase transition. Phys. Rev. A 66, 032110 (2002).

    Article  ADS  MathSciNet  Google Scholar 

  27. Parmigiani, F. & Sangaletti, L. Behaviour of the Zhang–Rice singlet in CuGeO3, Bi2CuO4, and CuO. J. Electron. Spectrosc. Relat. Phenom. 107, 49–62 (2000).

    Article  Google Scholar 

  28. Eccleston, R. S. et al. Spin dynamics of the spin-ladder dimer-chain material Sr14Cu24O41 . Phys. Rev. Lett. 81, 1702–1705 (1998).

    Article  ADS  Google Scholar 

  29. Lorenzo, J. E. et al. Macroscopic quantum coherence of the spin triplet in the spin-ladder compound Sr14Cu24O41 . Phys. Rev. Lett. 105, 097202 (2010).

    Article  ADS  Google Scholar 

  30. Jolicouer, Th. & Golinelli, O. Sigma-model study of Haldane-gap antiferromagnets. Phys. Rev. B 50, 9265–9273 (1994).

    Article  ADS  Google Scholar 

  31. Johnston, D. C. et al. Thermodynamics of spin s = 1/2 antiferromagnetic uniform and alternating-exchange Heisenberg chains. Phys. Rev. B 61, 9558–9606 (2000).

    Article  ADS  Google Scholar 

  32. Kataev, V. et al. Interplay of spin and charge dynamics in Sr14−xCaxCu24O41 . Phys. Rev. B 64, 104422 (2001).

    Article  ADS  Google Scholar 

  33. Klingeler, R. et al. Magnetism of hole-doped CuO2 spin chains in Sr14Cu24O41: Experimental and numerical results. Phys. Rev. B 73, 014426 (2006).

    Article  ADS  Google Scholar 

  34. Hase, M. 1/3 magnetization plateau observed in the s = 1/2 trimer chain compound Cu3(P2O6OH)2 . Phys. Rev. B 73, 104419 (2006).

    Article  ADS  Google Scholar 

  35. Oshikawa, M., Yamanaka, M. & Affleck, I. Magnetization plateaus in spin chains: Haldane gap for half-integer spins. Phys. Rev. Lett. 78, 1984–1987 (1997).

    Article  ADS  Google Scholar 

  36. Kageyama, H. et al. Exact dimer ground state and quantized magnetization plateaus in the two-dimensional spin system SrCu2(BO3)2 . Phys. Rev. Lett. 82, 3168–3171 (1999).

    Article  ADS  Google Scholar 

  37. Shiramura, W. et al. Magnetization plateaus in NH4CuCl3 . J. Phys. Soc. Jpn 67, 1548–1551 (1998).

    Article  ADS  Google Scholar 

  38. Ruegg, Ch. et al. Bose–Einstein condensation of the triplet states in the magnetic insulator TlCuCl3 . Nature 423, 62–65 (2003).

    Article  ADS  Google Scholar 

  39. Jaime, M. et al. Magnetic-field-induced condensation of triplons in Han purple pigment. Phys. Rev. Lett. 93, 087203 (2004).

    Article  ADS  Google Scholar 

  40. Sebastian, S. E. et al. Dimensional reduction at a quantum critical point. Nature 441, 617–620 (2006).

    Article  ADS  Google Scholar 

  41. Modi, K., Brodutch, A., Cable, H., Paterek, T. & Vedral, V. The classical-quantum boundary for correlations: Discord and related measures. Rev. Mod. Phys. 84, 1655–1707 (2012).

    Article  ADS  Google Scholar 

  42. Aldoshin, S. M., Fel’dman, E. B. & Yurishchev, M. A. Quantum entanglement and quantum discord in magnetoactive materials. Low Temp. Phys. 40, 1–16 (2014).

    Article  ADS  Google Scholar 

  43. Henderson, L. & Vedral, V. Classical, quantum and total correlations. J. Phys. A 34, 6899–6905 (2001).

    Article  ADS  MathSciNet  Google Scholar 

  44. Ollivier, H. & Zurek, W. H. Quantum discord: A measure of the quantumness of correlations. Phys. Rev. Lett. 88, 017901 (2001).

    Article  ADS  Google Scholar 

  45. Luo, S. Quantum discord for two-qubit systems. Phys. Rev. A 77, 042303 (2008).

    Article  ADS  Google Scholar 

Download references

Acknowledgements

We acknowledge the support of the European Community Research Infrastructures under the FP7 Capacities Specific Program, MICROKELVIN project number 228464.

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Contributions

The idea was born out of discussion between J.E.L. and S.S. Samples came from V.S., C.M. and A.R. The magnetization experiment was carried out by C.P., the specific heat experiment was carried out by G.R. and S.S. and the inelastic-neutron-scattering experiment was carried out on the three-axis spectrometer IN12 at ILL, Grenoble, by J.E.L., L.P.R. and S.R. The data were analysed by S.S. and J.E.L. Finally J.E.L. wrote the manuscript with input from all the authors.

Corresponding authors

Correspondence to S. Sahling or J. E. Lorenzo.

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The authors declare no competing financial interests.

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Sahling, S., Remenyi, G., Paulsen, C. et al. Experimental realization of long-distance entanglement between spins in antiferromagnetic quantum spin chains. Nature Phys 11, 255–260 (2015). https://doi.org/10.1038/nphys3186

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