Skip to main content
SpringerLink
Log in

Polarized Time-Resolved Spectroscopy of Electronic Phase Separation in a Dimer-Mott Organic Insulator

  • Original Paper
  • Published:
Journal of Superconductivity and Novel Magnetism Aims and scope Submit manuscript

Abstract

The electronic state of the organic single crystal \(\kappa -\left [ \left (\text {d-BEDT-TTF} \right )_{0.5} \left (\text {h-BEDT-TTF}\right )_{0.5}\right ]_{2}\) Cu[N(CN)2]Br, in which \(\sim \) 50 percent of the BEDT-TTF molecules are substituted by fully deuterated molecules (d-BEDT-TTF), has been characterized by resistance and polarized time-resolved spectroscopy measurements. We found that while the resistance shows no sign of a superconducting transition, the polarized time-resolved spectroscopy reveals a slow decay dynamics associated with the superconducting phase at a low temperature. The result suggests phase separation between the insulating and superconducting phases in the vicinity of the first-order Mott transition. In addition, we found that this slow component shows a steep increase below \(\sim \) 18 K, suggesting a fluctuating superconductivity in the conducting domains. Furthermore, the component persists up to at least \(\sim \) 50 K, which is almost consistent with the onset temperature of the anomalous magnetic-field-dependent signals observed by the previous Nernst effect measurements (Nam et al. Sci. Rep.3:3390, 2013) of the alloy κ-(BEDT-TTF)2Cu[N(CN)2]Cl0.27Br0.73. While interpretation of these anomalies is still debatable, there exists a possibility of the onset of superconducting paring at a very high temperature.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others

References

  1. Madan, I., Kurosawa, T., Toda, Y., Oda, M., Mertelj, T., Mihailovic, D.: Evidence for carrier localization in the pseudogap state of cuprate superconductors from coherent quench experiments. Nat. Commun. 6, 6958 (2015)

    Article  ADS  Google Scholar 

  2. Lang, K.M., Madhavan, V., Hoffman, J.E., Hudson, E.W., Eisaki, H., Uchida, S., Davis, J.C.: Imaging the granular structure of high-Tc superconductivity in underdoped Bi2Sr2CaCu2O8+δ. Nature 415(6870), 412–416 (2002). https://doi.org/10.1038/415412a

    Article  ADS  Google Scholar 

  3. Bianconi, A.: Multiplet splitting of final-state configurations in x-ray-absorption spectrum of metal VO2: effect of core-hole-screening, electron correlation, and metal-insulator transition. Phys. Rev. B 26, 2741–2747 (1982). https://doi.org/10.1103/PhysRevB.26.2741. https://link.aps.org/doi/10.1103/PhysRevB.26.2741

    Article  ADS  Google Scholar 

  4. Campi, G., Bianconi, A., Poccia, N., Bianconi, G., Barba, L., Arrighetti, G., Innocenti, D., Karpinski, J., Zhigadlo, N.D., Kazakov, S.M., Burghammer, M., Mv, Zimmermann, Sprung, M., Ricci, A.: Inhomogeneity of charge-density-wave order and quenched disorder in a high-Tc superconductor. Nature 525, 359 (2015). https://doi.org/10.1038/nature14987

    Article  ADS  Google Scholar 

  5. Marcelli, A., Coreno, M., Stredansky, M., Xu, W., Zou, C., Fan, L., Chu, W., Wei, S., Cossaro, A., Ricci, A., Bianconi, A., D’Elia, A.: Nanoscale phase separation and lattice complexity in VO2: the metal–insulator transition investigated by XANES via Auger electron yield at the vanadium L23-edge and resonant photoemission. Condensed. Matter. 2(4), 38 (2017). https://doi.org/10.3390/condmat2040038. https://www.mdpi.com/2410-3896/2/4/38

    Article  Google Scholar 

  6. Ricci, A., Poccia, N., Joseph, B., Innocenti, D., Campi, G., Zozulya, A., Westermeier, F., Schavkan, A., Coneri, F., Bianconi, A., Takeya, H., Mizuguchi, Y., Takano, Y., Mizokawa, T., Sprung, M., Saini, N.L.: Direct observation of nanoscale interface phase in the superconducting chalcogenide KxFe2−ySe2 with intrinsic phase separation. Phys. Rev. B 91, 020503 (2015). https://doi.org/10.1103/PhysRevB.91.020503. https://link.aps.org/doi/10.1103/PhysRevB.91.020503

    Article  ADS  Google Scholar 

  7. Vojta, T.: Quantum phase transitions in electronic systems. Annalen der Physik 9(6), 403 (2000). https://doi.org/10.1002/1521-3889(200006)9:6<403::AID-ANDP403>3.0.CO;2-R. https://onlinelibrary.wiley.com/doi/abs/10.1002/1521-3889%28200006%299%3A6%3C403%3A%3AAID-ANDP403%3E3.0.CO%3B2-R

    Article  ADS  MATH  Google Scholar 

  8. Efetov, K.B., Meier, H., Pépin, C: Pseudogap state near a quantum critical point. Nat. Phys. 9(7), 442 (2013). https://doi.org/10.1038/nphys2641

    Article  Google Scholar 

  9. Kanoda, K.: Metal-insulator transition in κ-(ET)2X and (DCNQI)2M: two contrasting manifestation of electron correlation. J. Phys. Soc. Jpn. 75 (5), 051007 (2006). https://doi.org/10.1143/JPSJ.75.051007

    Article  ADS  Google Scholar 

  10. Kini, A.M., Geiser, U., Wang, H.H., Carlson, K.D., Williams, J.M., Kwok, W.K., Vandervoort, K.G., Thompson, J.E., DLa, Stupka: A new ambient-pressure organic superconductor, kappa-(ET)2Cu[N(CN)2]Br, with the highest transition temperature yet observed (inductive onset Tc = 11.6 K, resistive onset = 12.5 K). Inorg. Chem. 29(14), 2555–2557 (1990). https://doi.org/10.1021/ic00339a004

    Article  Google Scholar 

  11. Miyagawa, K., Kawamoto, A., Nakazawa, Y., Kanoda, K.: Antiferromagnetic ordering and spin structure in the organic conductor, κ-(BEDT-TTF)2Cu[N(CN)2]Cl. Phys. Rev. Lett. 75, 1174–1177 (1995). https://doi.org/10.1103/PhysRevLett.75.1174. https://link.aps.org/doi/10.1103/PhysRevLett.75.1174

    Article  ADS  Google Scholar 

  12. Sasaki, T., Yoneyama, N., Suzuki, A., Kobayashi, N., Ikemoto, Y., Kimura, H.: Real space imaging of the metal-insulator phase separation in the band width controlled organic Mott system κ-(BEDT-TTF)2Cu[N(CN)2]Br. J. Physical. Soc. Japan. 74(8), 2351–2360 (2005). https://doi.org/10.1143/JPSJ.74.2351

    Article  ADS  Google Scholar 

  13. Uehara, T., Ito, M., Angel, J., Shimada, J., Komakine, N., Tsuchiya, T., Taniguchi, H., Satoh, K., Triyana, K., Ishii, Y., Watanabe, I.: Studies on magnetism of the layered organic antiferromagnet bordered on a superconducting phase by muon spin rotation and magnetization measurements. J. Phys. Soc. Jpn. 85(2), 024710 (2016). https://doi.org/10.7566/JPSJ.85.024710

    Article  ADS  Google Scholar 

  14. Yoneyama, N., Sasaki, T., Kobayashi, N.: Substitution effect by deuterated donors on superconductivity in κ-(BEDT-TTF)2Cu[N(Cn)2]Br. J. Physical. Soc. Japan. 73(6), 1434–1437 (2004). https://doi.org/10.1143/JPSJ.73.1434

    Article  ADS  Google Scholar 

  15. Nakagawa, K., Tsuchiya, S., Yamada, J., Toda, Y.: Pump- and probe-polarization analyses of ultrafast carrier dynamics in organic superconductors. J. Supercond. Nov. Magn. 29(12), 3065–3069 (2016). https://doi.org/10.1007/s10948-016-3741-6

    Article  Google Scholar 

  16. Nakagawa, K., Tsuchiya, S., Yamada, J., Toda, Y.: Fluctuating superconductivity in κ-type organic compounds probed by polarized time-resolved spectroscopy. EPL (Europhysics Letters) 122(6), 67003 (2018). https://doi.org/10.1209/0295-5075/122/67003

    Article  ADS  Google Scholar 

  17. Toda, Y., Mertelj, T., Naito, T., Mihailovic, D.: Femtosecond carrier relaxation dynamics and photoinduced phase separation in κ-(BEDT-TTF)2Cu[N(CN)2]X (X = Br,Cl). Phys. Rev. Lett. 107, 227002 (2011). https://doi.org/10.1103/PhysRevLett.107.227002. https://link.aps.org/doi/10.1103/PhysRevLett.107.227002

    Article  ADS  Google Scholar 

  18. Tsuchiya, S., Nakagawa, K., Taniguchi, H., Toda, Y.: Polarization-resolved ultrafast spectroscopy in an organic Mott insulator κ-(BEDT-TTF)2Cu[N(CN)2]Cl. J. Phys. Soc. Jpn. 88(7), 074706 (2019). https://doi.org/10.7566/JPSJ.88.074706

    Article  ADS  Google Scholar 

  19. Tsuchiya, S., Nakagawa, K., Yamada, J., Taniguchi, H., Toda, Y.: Photoinduced phase separation with local structural ordering in organic molecular conductors. Phys. Rev. B 96, 134311 (2017). https://doi.org/10.1103/PhysRevB.96.134311. https://link.aps.org/doi/10.1103/PhysRevB.96.134311

    Article  ADS  Google Scholar 

  20. Giannetti, C., Capone, M., Fausti, D., Fabrizio, M., Parmigiani, F., Mihailovic, D.: Ultrafast optical spectroscopy of strongly correlated materials and high-temperature superconductors: a non-equilibrium approach. Adv. Phys. 65(2), 58–238 (2016). https://doi.org/10.1080/00018732.2016.1194044

    Article  ADS  Google Scholar 

  21. Kabanov, V.V., Demsar, J., Podobnik, B., Mihailovic, D.: Quasiparticle relaxation dynamics in superconductors with different gap structures: theory and experiments on YBa2Cu3O7−δ. Phys. Rev. B 59, 1497–1506 (1999). https://doi.org/10.1103/PhysRevB.59.1497. https://link.aps.org/doi/10.1103/PhysRevB.59.1497

    Article  ADS  Google Scholar 

  22. Luo, C.W., Chung Cheng, P., Wang, S.H., Chiang, J.C., Lin, J.Y., Wu, K.H., Juang, J.Y., Chareev, D.A., Volkova, O.S., Vasiliev, A.N.: Unveiling the hidden nematicity and spin subsystem in FeSe. npj. Quantum Materials 2(1), 32 (2017). https://doi.org/10.1038/s41535-017-0036-5

    Article  ADS  Google Scholar 

  23. Toda, Y., Kawanokami, F., Kurosawa, T., Oda, M., Madan, I., Mertelj, T., Kabanov, V.V., Mihailovic, D.: Rotational symmetry breaking in Bi2Sr2CaCu2O8+δ probed by polarized femtosecond spectroscopy. Phys. Rev. B 90, 094513 (2014). https://doi.org/10.1103/PhysRevB.90.094513. https://link.aps.org/doi/10.1103/PhysRevB.90.094513

    Article  ADS  Google Scholar 

  24. Tsuchiya, S., Sugawara, Y., Tanda, S., Toda, Y.: Symmetry-dependent carrier relaxation dynamics and charge–density–wave transition in DyTe3 probed by polarized femtosecond spectroscopy. J Optics 17(8), 085501 (2015). http://stacks.iop.org/2040-8986/17/i=8/a=085501

    Article  ADS  Google Scholar 

  25. Urayama, H., Yamochi, H., Saito, G., Nozawa, K., Sugano, T., Kinoshita, M., Sato, S., Oshima, K., Kawamoto, A., Tanaka, J.: A new ambient pressure organic superconductor based on BEDT-TTF with Tc higher than 10 K (Tc= 10.4 K). Chem. Lett. 17(1), 55–58 (1988). https://doi.org/10.1246/cl.1988.55

    Article  Google Scholar 

  26. Nam, M.S., Méziere, C, Batail, P., Zorina, L., Simonov, S., Ardavan, A.: Superconducting fluctuations in organic molecular metals enhanced by Mott criticality. Sci. Rep. 3, 3390 (2013)

    Article  Google Scholar 

  27. Anzai, H., Delrieu, J., Takasaki, S., Nakatsuji, S., Yamada, J.: Crystal growth of organic charge-transfer complexes by electrocrystallization with controlled applied current. J. Cryst. Growth. 154(1), 145–150 (1995). https://doi.org/10.1016/0022-0248(95)00144-1. http://www.sciencedirect.com/science/article/pii/0022024895001441

    Article  ADS  Google Scholar 

  28. Müller, J., Lang, M., Steglich, F., Schlueter, J.A., Kini, A.M., Sasaki, T.: Evidence for structural and electronic instabilities at intermediate temperatures in κ-(BEDT-TTF)2X for X = Cu[N(CN)2]Cl,Cu[N(CN)2]Br and Cu(NCS)2 : implications for the phase diagram of these quasi-two-dimensional organic superconductors. Phys. Rev. B 65, 144521 (2002). https://doi.org/10.1103/PhysRevB.65.144521. https://link.aps.org/doi/10.1103/PhysRevB.65.144521

    Article  ADS  Google Scholar 

  29. Nam, M.S., Ardavan, A., Blundell, S.J., Schlueter, J.A.: Fluctuating superconductivity in organic molecular metals close to the Mott transition. Nature 449(7162), 584–587 (2007). https://doi.org/10.1038/nature06182

    Article  ADS  Google Scholar 

  30. Uehara, T., Ito, M., Taniguchi, H., Satoh, K.: Superconducting fluctuation of the layered organic superconductor κ-(BEDT-TTF)2Cu[N(CN)2]Br in magnetic susceptibility. J. Phys. Soc. Jpn. 82(7), 073706 (2013). https://doi.org/10.7566/JPSJ.82.073706

    Article  ADS  Google Scholar 

  31. Sasaki, T., Yoneyama, N., Kobayashi, N., Ikemoto, Y., Kimura, H.: Imaging phase separation near the Mott boundary of the correlated organic superconductors κ-(BEDT-TTF)2X. Phys. Rev. Lett. 92, 227001 (2004). https://doi.org/10.1103/PhysRevLett.92.227001. https://link.aps.org/doi/10.1103/PhysRevLett.92.227001

    Article  ADS  Google Scholar 

Download references

Acknowledgments

We thank Edanz Group (www.edanzediting.com/ac) for editing a draft of this manuscript.

Funding

This work was supported by JSPS KAKENHI Grant Numbers 15K17685, 18J10148, and 19H05826.

Author information

Authors and Affiliations

  1. Department of Applied Physics, Graduate School of Engineering, Hokkaido University, Sapporo, 060-8628, Japan

    Koichi Nakagawa, Satoshi Tsuchiya & Yasunori Toda

  2. Graduate School of Science and Engineering, Saitama University, Saitama, 338-8570, Japan

    Hiromi Taniguchi

Authors
  1. Koichi Nakagawa
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Satoshi Tsuchiya
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Hiromi Taniguchi
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Yasunori Toda
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Koichi Nakagawa.

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

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Nakagawa, K., Tsuchiya, S., Taniguchi, H. et al. Polarized Time-Resolved Spectroscopy of Electronic Phase Separation in a Dimer-Mott Organic Insulator. J Supercond Nov Magn 33, 2427–2433 (2020). https://doi.org/10.1007/s10948-019-05385-1

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10948-019-05385-1

Keywords

Search

Navigation