Abstract
The discovery of superconductivity at 203 K in highly compressed sulphur hydride validates the ideas put forward by Ashcroft 50 years ago and galvanises the quest for room-temperature superconductivity. But at such temperatures, thermal fluctuations might be expected to break up Cooper pairs. For example, in the cuprates, fluctuations reduce T c by 30% or more below the mean-field value. Similar effects are found in iron pnictides. Here, we ask: how does superconductivity survive in sulphur hydride at such high temperatures? To answer this, we examine the superfluid density which is the key parameter for quantifying fluctuations in both amplitude and phase. We show that dimensionality plays a key role in suppressing or enhancing thermal fluctuations to the benefit of hydrogen sulphide and the detriment of its more layered 2D competitors. We find that the temperature scale for phase fluctuations, T φ , in superconducting H3S exceeds 1200 K, and therefore, these are irrelevant at 200 K. But the amplitude fluctuation temperature scale, T amp, at around 300 K is much lower and this has important implications for the ongoing quest for room temperature superconductivity. Appealing to the way in which superfluid density, T φ , T amp and T c scale with each other it seems that room temperature superconductivity is nearly ruled out, but perhaps not quite. It will require 3D systems with a large Fermi velocity to achieve this goal.
Similar content being viewed by others
References
Wigner, E., Huntington, H.B.: On the possibility of a metallic modification of hydrogen. J. Chem. Phys. 3, 764 (1935)
Dias, R., Silvera, I.F.: Observation of the Wigner-Huntington transition to solid metallic hydrogen. Science. 355, 715–718 (2017)
Eremets, M.I., Drozdov, A.P.: Comments on the claimed observation of the Wigner-Huntington Transition to Metallic Hydrogen. arXiv:http://arXiv.org/abs/1702.05125 (2017)
Ashcroft, N.W.: Metallic hydrogen: A high-temperature superconductor? Phys. Rev. Lett. 21, 1748–1749 (1968)
Ashcroft, N.W.: Hydrogen dominant metallic alloys: High temperature superconductors? Phys. Rev. Lett. 92, 187002 (2004)
Li, Y., Hao, J., Liu, H., Li, Y., Ma, Y.: The metallization and superconductivity of dense hydrogen sulfide. J. Chem. Phys. 140, 174712 (2014)
Drozdov, A.P., Eremets, M.I., Troyan, I.A., Ksenofontov, V., Shylin, S.I.: Conventional superconductivity at 203 kelvin at high pressures in the sulfur hydride system. Nature 525, 73–76 (2015)
Duan, D., Liu, Y., Tian, F., Li, D., Huang, X., Zhao, Z., Yu, H., Liu, B., Tian, W., Cui, T.: Sci. Rep. 4, 6968 (2014)
Einaga, M., Sakata, M., Ishikawa, T., Shimizu, K., Eremets, M.I., Drozdov, A.P., Troyan, I.A., Hirao, N., Ohishi, Y.: Crystal structure of the superconducting phase of sulfur hydride. Nat. Phys. 12, 835–838 (2016)
Tallon, J.L., Storey, J.G., Loram, J.W.: Fluctuations and critical temperature reduction in cuprate superconductors. Phys. Rev. B 83, 092502 (2011)
Shibauchi, T., Carrington, A., Matsuda, Y.: quantum critical point lying beneath the superconducting dome in iron pnictides. Annu. Rev. Condens. Matter Phys. 5, 113–135 (2014)
Knebel, G., Aoki, D., Braithwaite, D., Salce, B., Flouquet, J.: Coexistence of antiferromagnetism and superconductivity in CeRhIn5 under high pressure and magnetic field. Phys. Rev. B 74, 020501 (2006)
Morosan, E., Zandbergen, H.W., Dennis, B.S., Bos, J.W.G., Onose, Y., Klimczuk, T., Ramirez, A.P., Ong, N.P., Cava, R.J.: Superconductivity in Cu x TiSe2. Nat. Phys. 2, 544–550 (2006)
Goh, S.K., Tompsett, D.A., Saines, P.J., Chang, H.C., Matsumoto, T., Imai, M., Yoshimura, K., Grosche, F.M.: F.M. Ambient pressure structural quantum critical point in the phase diagram of (Ca x Sr1x )3Rh4Sn13. Phys. Rev. Lett. 114, 097002 (2015)
Tallon, J.L., Barber, F., Storey, J.G., Loram, J.W.: Coexistence of the superconducting energy gap and pseudogap above and below the transition temperature of cuprate superconductors. Phys. Rev. B 87, 140508(R) (2013)
Storey, J.G.: Incoherent superconductivity well above T c in high- T c cuprates - harmonizing the spectroscopic and thermodynamic data. New J. Phys. 19, 073026 (2017)
Jacobs, T. h., Katterwe, S.O., Krasnov, V.M.: Superconducting correlations above T c in the pseudogap state of Bi2Sr2CaCu2 O 8 + δ cuprates revealed by angular-dependent magnetotunneling. Phys. Rev. B 94, 220501(R) (2016)
Larkin, A., Varlamov, A.: Theory of Fluctuations in Superconductors, p 230. Oxford University Press, Oxford (2005)
Poole, C.P., Farach, H.A., Creswick, R.J., Prozorov, R.: Superconductivity, p 343. Academic Press, London (2007)
Talantsev, E.F., Crump, W.P., Storey, J.G., Tallon, J.L.: London penetration depth and thermal fluctuations in the sulphur hydride 203 K superconductor. Ann. Phys. (Berlin) 529, 1600390 (2017)
Emery, V.J., Kivelson, S.A.: Importance of phase fluctuations in superconductors with small superfluid density. Nature 374, 434–437 (1995)
Bulaevskii, L.N., Ginzburg, V.L., Sobyanin, A.A.: Macroscopic theory of superconductors with small coherence length. Phys. C 152, 378–388 (1988)
Uemura, Y.J. et al.: Basic similarities among cuprate, bismuthate, organic, Chevrel-phase, and heavy-fermion superconductors shown by penetration-depth measurements. Phys. Rev. Lett. 66, 2665–2668 (1991)
Werthamer, N.R., Helfand, E., Hohenberg, P.C.: Temperature and purity dependence of the superconducting critical field, H c2. III. Electron spin and spin-orbit effects. Phys. Rev. 147, 295–302 (1966)
Talantsev, E.F., Tallon, J.L.: Universal self-field critical current for thin-film superconductors. Nature Comms. 6, 7820–7827 (2015)
Talantsev, E.F., Crump, W.P., Tallon, J.L.: Thermodynamic parameters of single- or multi-band superconductors derived from self-field critical currents. Ann. Physik 529, 1700197 (2017)
Talantsev, E.F., Crump, W.P., Island, J.O., Xing, Y., Sun, Y., Wang, J., Tallon, J.L.: On the origin of critical temperature enhancement in atomically thin superconductors. 2D Mater. 4, 025072 (2017)
Talantsev, E.F., Crump, W.P., Tallon, J.L.: Universal scaling of the self-field critical current in superconductors: from sub-nanometre to millimetre size. Sci. Rep. 7, 10010 (2017)
Pearl, J.: Current distribution in superconducting films carrying quantized fluxoids. Appl. Phys. Lett. 5, 65–66 (1964)
Rhoderick, E.H., Wilson, E.M.: Current distribution in thin superconducting films. Nature 194, 1167–1168 (1962)
Bean, C.P.: Magnetization of high-field superconductors. Rev. Mod. Phys. 36, 31–39 (1964)
Johansen, T.H., Bratsberg, H.J.: Critical-state magnetization of type-II superconductors in rectangular slab and cylindrical geometries. Appl. Phys. 77, 3945–3952 (1995)
Grasso, G., Cimberle, M.R., Ferdeghini, C., Siri, A.S.: Temperature dependence of the intragrain critical current density in polycrystalline Ag-sheathed Bi(2223) tapes. IEEE Trans. Appl. Supercond. 9, 2667–2670 (1999)
Cichorek, T., Mota, A.C., Steglich, F., Frederick, N.A., Yuhasz, W.M., Maple, M.B.: Pronounced enhancement of the lower critical field and critical current deep in the superconducting state of PrOs4,Sb12. Phys. Rev. Lett. 94, 107002 (2005)
Tai, M.F., Chang, G.F., Lee, M.W.: Vortex-lattice melting in superconducting fullerene Rb3 C 60. Phys. Rev B 52, 1176–1180 (1995)
Acknowledgements
JLT and EFT separately thank the Marsden Fund of New Zealand for financial support (JLT: grant number VUW1322, EFT: grant number VUW1608).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Tallon, J., Talantsev, E. Compressed H3S, Superfluid Density and the Quest for Room-Temperature Superconductivity. J Supercond Nov Magn 31, 619–624 (2018). https://doi.org/10.1007/s10948-017-4419-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10948-017-4419-4