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Physical realization of a quantum spin liquid based on a complex frustration mechanism

Abstract

Unlike conventional magnets where the magnetic moments are partially or completely static in the ground state, in a quantum spin liquid they remain in collective motion down to the lowest temperatures. The importance of this state is that it is coherent and highly entangled without breaking local symmetries. In the case of magnets with isotropic interactions, spin-liquid behaviour is sought in simple lattices with antiferromagnetic interactions that favour antiparallel alignments of the magnetic moments and are incompatible with the lattice geometries. Despite an extensive search, experimental realizations remain very few. Here we investigate the novel, unexplored magnet Ca10Cr7O28, which has a complex Hamiltonian consisting of several different isotropic interactions and where the ferromagnetic couplings are stronger than the antiferromagnetic ones. We show both experimentally and theoretically that it displays all the features expected of a quantum spin liquid. Thus spin-liquid behaviour in isotropic magnets is not restricted to the simple idealized models currently investigated, but can be compatible with complex structures and ferromagnetic interactions.

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Figure 1: Structure and Hamiltonian.
Figure 2: Specific heat and a.c. susceptibility.
Figure 3: μSR data.
Figure 4: Inelastic neutron scattering data measured in zero applied magnetic field.
Figure 5: Inelastic neutron scattering data measured in zero applied magnetic field compared to theory.

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References

  1. Anderson, P. W. Resonating valence bonds: a new kind of insulator? Mater. Res. Bull. 8, 153–160 (1973).

    Article  Google Scholar 

  2. Balents, L. Spin liquids in frustrated magnets. Nature 464, 199–208 (2010).

    Article  ADS  Google Scholar 

  3. Fennell, T. et al. Magnetic coulomb phase in the spin ice Ho2Ti2O7 . Science 326, 415–417 (2009).

    Article  ADS  Google Scholar 

  4. Morris, D. J. P. et al. Dirac strings and magnetic monopoles in the spin ice Dy2Ti2O7 . Science 326, 411–414 (2009).

    Article  ADS  Google Scholar 

  5. Kitaev, A. Anyons in an exactly solved model and beyond. Ann. Phys. 321, 2–111 (2006).

    Article  ADS  MathSciNet  Google Scholar 

  6. Banerjee, A. et al. Proximate Kitaev quantum spin liquid behaviour in a honeycomb magnet. Nature Mater. http://dx.doi.org/10.1038/nmat4604 (2016).

  7. Yan, S., Huse, D. A. & White, S. R. Spin-liquid ground state of the s = 1/2 kagome Heisenberg antiferromagnet. Science 332, 1173–1176 (2011).

    Article  ADS  Google Scholar 

  8. Depenbrock, S., McCulloch, I. P. & Schollwöck, U. Nature of the spin-liquid ground state of the s = 1/2 Heisenberg model on the kagome lattice. Phys. Rev. Lett. 109, 067201 (2012).

    Article  ADS  Google Scholar 

  9. Wan, Y. & Tchernyshyov, O. Phenomenological Z2 lattice gauge theory of the spin-liquid state of the kagome Heisenberg antiferromagnet. Phys. Rev. B 87, 104408 (2013).

    Article  ADS  Google Scholar 

  10. Iqbal, Y., Becca, F., Sorella, S. & Poilblanc, D. Gapless spin-liquid phase in the kagome spin-1/2 Heisenberg antiferromagnet. Phys. Rev. B 87, 060405 (2013).

    Article  ADS  Google Scholar 

  11. Punk, M., Chowdhury, D. & Sachdev, S. Topological excitations and the dynamic structure factor of spin liquids on the kagome lattice. Nature Phys. 10, 289–293 (2014).

    Article  ADS  Google Scholar 

  12. Suttner, R., Platt, C., Reuther, J. & Thomale, R. Renormalization group analysis of competing quantum phases in the J1–J2 Heisenberg model on the kagome lattice. Phys. Rev. B 89, 020408 (2014).

    Article  ADS  Google Scholar 

  13. Han, T.-H. et al. Fractionalized excitations in the spin-liquid state of a kagome-lattice antiferromagnet. Nature 492, 406–410 (2012).

    Article  ADS  Google Scholar 

  14. Fu, M., Imai, T., Han, T.-H. & Lee, Y. S. Evidence for a gapped spin-liquid ground state in a kagome Heisenberg antiferromagnet. Science 350, 655–658 (2015).

    Article  ADS  Google Scholar 

  15. Gyepesova, D. & Langer, V. Ca10(CrVO4)6(CrVIO4), a disordered mixed-valence chromium compound exhibiting inversion twinning. Acta Cryst. C69, 111–113 (2013).

    Google Scholar 

  16. Read, N. & Sachdev, S. Valence-bond and spin-Peierls ground states of low-dimensional quantum antiferromagnets. Phys. Rev. Lett. 62, 1694–1697 (1989).

    Article  ADS  Google Scholar 

  17. Mydosh, J. A. Spin Glasses: An Experimental Introduction (Taylor and Francis, 1993).

    Google Scholar 

  18. Mehlawat, K., Sharma, G. & Singh, Y. Fragile magnetic order in the honeycomb lattice iridate Na2IrO3 revealed by magnetic impurity doping. Phys. Rev. B 92, 134412 (2015).

    Article  ADS  Google Scholar 

  19. Cole, K. S. & Cole, R. H. Dispersion and absorption in dielectrics i. Alternating current characteristics. J. Chem. Phys. 9, 341–351 (1941).

    Article  ADS  Google Scholar 

  20. Yaouanc, A. & Dalmas de Rotier, P. Muon Spin Rotation, Relaxation and Resonance (Oxford Univ. Press, 2011).

    Google Scholar 

  21. Mendels, P. et al. Quantum magnetism in the paratacamite family: towards an ideal kagomé lattice. Phys. Rev. Lett. 98, 077204 (2007).

    Article  ADS  Google Scholar 

  22. Fåk, B. et al. Kapellasite: a kagome quantum spin liquid with competing interactions. Phys. Rev. Lett. 109, 037208 (2012).

    Article  ADS  Google Scholar 

  23. Clark, L. et al. Gapless spin liquid ground state in the S = 1/2 vanadium oxyfluoride kagome antiferromagnet [NH4]2[C7H14N][V7O6F18]. Phys. Rev. Lett. 110, 207208 (2013).

    Article  ADS  Google Scholar 

  24. Squires, G. L. Introduction to the Theory of Thermal Neutron Scattering (Dover, 1996).

    Google Scholar 

  25. Carlo, J. P. et al. Triplet and in-gap magnetic states in the ground state of the quantum frustrated fcc antiferromagnet Ba2YMoO6 . Phys. Rev. B 84, 100404 (2011).

    Article  ADS  Google Scholar 

  26. de Vries, M. A., Mclaughlin, A. C. & Bos, J.-W. G. Valence bond glass on an fcc lattice in the double perovskite Ba2YMoO6 . Phys. Rev. Lett. 104, 177202 (2010).

    Article  ADS  Google Scholar 

  27. Faddeev, L. D. & Takhtajan, L. A. What is the spin of a spin wave? Phys. Lett. A 85, 375–377 (1981).

    Article  ADS  MathSciNet  Google Scholar 

  28. Lake, B., Tennant, D. A., Frost, C. D. & Nagler, S. E. Quantum criticality and universal scaling of a quantum antiferromagnet. Nature Mater. 4, 329–334 (2005).

    Article  ADS  Google Scholar 

  29. Caux, J.-S. & Hagemans, R. The four-spinon dynamical structure factor of the Heisenberg chain. J. Stat. Mech. P12013 (2006).

  30. Lake, B. et al. Multispinon continua at zero and finite temperature in a near-ideal Heisenberg chain. Phys. Rev. Lett. 111, 137205 (2013).

    Article  ADS  Google Scholar 

  31. Mourigal, M. et al. Fractional spinon excitations in the quantum Heisenberg antiferromagnetic chain. Nature Phys. 9, 435–441 (2013).

    Article  ADS  Google Scholar 

  32. Balz, C. et al. Quantum spin chain as a potential realization of the Nersesyan–Tsvelik model. Phys. Rev. B 90, 060409 (2014).

    Article  ADS  Google Scholar 

  33. Liang, S., Doucot, B. & Anderson, P. W. Some new variational resonating-valence-bond-type wave functions for the spin-1/2 antiferromagnetic Heisenberg model on a square lattice. Phys. Rev. Lett. 61, 365–368 (1988).

    Article  ADS  Google Scholar 

  34. Read, N. & Chakraborty, B. Statistics of the excitations of the resonating-valence-bond state. Phys. Rev. B 40, 7133–7140 (1989).

    Article  ADS  Google Scholar 

  35. Read, N. & Sachdev, S. Large-N expansion for frustrated quantum antiferromagnets. Phys. Rev. Lett. 66, 1773–1776 (1991).

    Article  ADS  Google Scholar 

  36. Wen, X. G. Mean-field theory of spin-liquid states with finite energy gap and topological orders. Phys. Rev. B 44, 2664–2672 (1991).

    Article  ADS  Google Scholar 

  37. Wen, X.-G. Quantum orders and symmetric spin liquids. Phys. Rev. B 65, 165113 (2002).

    Article  ADS  Google Scholar 

  38. Coldea, R. et al. Direct measurement of the spin Hamiltonian and observation of condensation of magnons in the 2D frustrated quantum magnet Cs2CuCl4 . Phys. Rev. Lett. 88, 137203 (2002).

    Article  ADS  Google Scholar 

  39. Ross, K. A., Savary, L., Gaulin, B. D. & Balents, L. Quantum excitations in quantum spin ice. Phys. Rev. X 1, 021002 (2011).

    Google Scholar 

  40. Toth, S. & Lake, B. Linear spin wave theory for single-Q incommensurate magnetic structures. J. Phys. Condens. Matter 27, 166002 (2015).

    Article  ADS  Google Scholar 

  41. Reuther, J. & Wölfle, P. J1–J2 frustrated two-dimensional Heisenberg model: random phase approximation and functional renormalization group. Phys. Rev. B 81, 144410 (2010).

    Article  ADS  Google Scholar 

  42. Reuther, J. & Thomale, R. Functional renormalization group for the anisotropic triangular antiferromagnet. Phys. Rev. B 83, 024402 (2011).

    Article  ADS  Google Scholar 

  43. Reuther, J., Thomale, R. & Rachel, S. Spiral order in the honeycomb iridate Li2IrO3 . Phys. Rev. B 90, 100405 (2014).

    Article  ADS  Google Scholar 

  44. Chernyshev, A. L. & Zhitomirsky, M. E. Spin waves in a triangular lattice antiferromagnet: decays, spectrum renormalization, and singularities. Phys. Rev. B 79, 144416 (2009).

    Article  ADS  Google Scholar 

  45. Frontzek, M. et al. Magnetic excitations in the geometric frustrated multiferroic CuCrO2 . Phys. Rev. B 84, 094448 (2011).

    Article  ADS  Google Scholar 

  46. Kubo, R. & Toyabe, T. Magnetic Resonance and Relaxation (North-Holland, 1967).

    Google Scholar 

  47. Suter, A. & Wojek, B. M. Musrfit: a free platform-independent framework for μsr data analysis. Phys. Proc. 30, 69–73 (2012).

    Article  ADS  Google Scholar 

  48. Metzner, W., Salmhofer, M., Honerkamp, C., Meden, V. & Schönhammer, K. Functional renormalization group approach to correlated fermion systems. Rev. Mod. Phys. 84, 299–352 (2012).

    Article  ADS  Google Scholar 

  49. Platt, C., Hanke, W. & Thomale, R. Functional renormalization group for multi-orbital fermi surface instabilities. Adv. Phys. 62, 453–562 (2013).

    Article  ADS  Google Scholar 

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Acknowledgements

We thank S. Toth for his help with the SpinW program and E. J. Bergholtz for helpful discussions. We acknowledge the Helmholtz Gemeinschaft for funding via the Helmholtz Virtual Institute (Project No. HVI-521) and DFG through Research Training Group GRK 1621 and SFB 1143. We also acknowledge the support of the HLD-HZDR, a member of the European Magnetic Field Laboratory (EMFL). This work used facilities supported in part by the National Science Foundation under Agreement No. DMR-1508249. J.R. was supported by the Freie Universität Berlin, within the Excellence Initiative of the German Research Foundation.

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Contributions

C.B. performed or participated in all measurements, and analysed the data with help from the other authors. B.L. directed the project, participated in most measurements, and wrote the manuscript with contributions from all authors. J.R. carried out the PFFRG calculations and provided theoretical insight. Y.S. introduced the compound and made the powder, while the crystals were grown by Y.S. and A.T.M.N.I.; H.R. carried out the specific heat measurements; R.S. and T.H. performed the AC susceptibility measurements and helped with the analysis; C.B. and H.L. helped with the μSR measurements and with their analysis; E.M.W., J.A.R.-R., T.G. and G.G.S. supported the INS measurements.

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Correspondence to Christian Balz.

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The authors declare no competing financial interests.

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Balz, C., Lake, B., Reuther, J. et al. Physical realization of a quantum spin liquid based on a complex frustration mechanism. Nature Phys 12, 942–949 (2016). https://doi.org/10.1038/nphys3826

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