1 / 29

Kitaoka Lab. M1 Ryuji Michizoe

Superconductivity and non-Fermi-liquid behavior of Ce 2 PdIn 8. V. H. Tran et al., PHYSICAL REVIEW B 83 , 064504 (2011). Kitaoka Lab. M1 Ryuji Michizoe. Contents. ・ Introduction - History of Superconductivity - Heavy fermion system ・ R esults ・ Summary. 1900. 1920. 1940.

jasia
Download Presentation

Kitaoka Lab. M1 Ryuji Michizoe

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Superconductivity and non-Fermi-liquid behavior of Ce2PdIn8 V. H. Tran et al., PHYSICAL REVIEW B 83, 064504 (2011) KitaokaLab. M1 Ryuji Michizoe

  2. Contents ・Introduction - History of Superconductivity - Heavy fermion system ・Results ・Summary

  3. 1900 1920 1940 1960 1980 2000 2020 Year History of Superconductivity(SC) Discovery of superconducting phenomenon 200 metal 1911 heavy fermion system high-Tc cuprate 163 Hg-Ba-Ca-Cu-O iron-based system under high pressure （ ） 150 Hg-Ba-Ca-Cu-O Heavy fermion superconductor Tl-Ba-Ca-Cu-O 1986 1979 Bi-Sr-Ca-Cu-O 100 SC transition temperature-Tc(K) Y-Ba-Cu-O 77 High-Tccuprate superconductor SmO F FeAs 50 0.9 0.11 MgB2 La-Ba-Cu-O LaO F FeAs PuCoGa5 2006 Nb Ge 0.11 0.89 Nb Pb CeCu2Si2 NbN LaOFeP Hg NbC Iron-based high-Tc superconductor 0

  4. 4f 5p 5d n(r) 6s r Heavy fermion compounds CeCu2Si2 CePd2Si2CeRh2Si2CeIn3CeRhIn5 UPt3UPd2Al3 f electrons PrOs4Sb12 PuCoGa5etc

  5. Heavy fermionstate Normal metal ＋ ＋ ＋ ＋ ＋ ＋ Heavy fermion state f f f ＋ ＋ ＋ c-f hybridization f f f ＋ ＋ ＋ conduction electron

  6. Heavy fermion system RKKY interaction The interplay between two 4f electrons mediated by conduction electrons Conduction electron Polarization Jcf Jcf Magnetic Order 4f electron

  7. Heavy fermion system Kondo effect 4f and conduction electrons form a spin-singlet state Conduction electron Jcf Fermi Liquid 4f electron

  8. Phase Diagram of HF system TK ∝ W exp(-1/JcfD(εF)) TRKKY ∝ D(εF) Jcf2 AFM : antiferromagnetism HF: heavy fermion state QCP : quantumcritical point

  9. Kondo effect Conduction electron 4f electron Kondo effect

  10. P dependence ofTmax Above Tmax Incoherent Kondo scattering Below Tmax Coherent Kondo scattering

  11. P dependence of Tmax Tmaxshifts to high T Tmax∝TK

  12. Resistivity of Ce2PdIn8 1 bar Tc~ 0.7 K P decreasesTc

  13. The P dependence of TC P ~ 21 kbar SC disappears P suppresses SC

  14. Non-Fermi-liquid behavior Fermi-liquid ρ(T ) = ρ0 + AT 2 ρ(T ) = ρ0+ AT n (n < 2) Non-Fermi-liquid n = 1 : 2D antiferromagnetic spin fluctuation n = 1.5 : 3D antiferromagnetic spin fluctuation n = 2 : Fermi-liquid

  15. Pdependent values of n , A , ρ0 ρ(T ) = ρ0+ AT n A ∝ TK-2 n = 1 : 2D antiferromagnetic spin fluctuation n = 1.5 : 3D antiferromagnetic spin fluctuation n = 2 : Fermi-liquid

  16. Pdependent values of n , A , ρ0 ρ(T ) = ρ0+ AT n V. A. Sidorov et al., PRL 89.157004 (2002) AF spin fluctuation is supressed by increasing P n = 1 : 2D antiferromagnetic spin fluctuation n = 1.5 : 3D antiferromagnetic spin fluctuation n = 2 : Fermi-liquid

  17. The relationship between SC and AF spin fluctuation SC may be associated with AF spin fluctuation

  18. Field dependence of resistivity Below Hc2= 2.5 T ρ(T ) ∝ AT non-Fermi-liquid Above Hc2= 2.5 T ρ(T ) ∝ AT 2 Fermi-liquid n = 1 : 2D antiferromagnetic spin fluctuation n = 1.5 : 3D antiferromagnetic spin fluctuation n = 2 : Fermi-liquid TFL: Fermi-liquid temperature

  19. Field dependence of resistivity TFL increases with rising field Fermi-liquid is recovered at strong magnetic fields

  20. Field dependent values of n , A , ρ0 Hc2 ρ(T ) = ρ0+ AT n near Hc2 Fermi-liquid n : jump to n = 2 A : maximum ρ0: minimum AF spin fluctuations associated with a QCP n = 1 : 2D antiferromagnetic spin fluctuation n = 1.5 : 3D antiferromagnetic spin fluctuation n = 2 : Fermi-liquid

  21. Summary Hc2 n = 1 : 2D antiferromagnetic spin fluctuation n = 1.5 : 3D antiferromagnetic spin fluctuation n = 2 : Fermi-liquid SC in Ce2PdIn8 may be mediated by the AF spin fluctuations

  22. END

  23. Ce2PdIn8 H. Fukazawaet al., PHYSICAL REVIEW B 86, 094508 (2012)

  24. Heavy fermion system RKKY interaction Kondo effect Conduction electron Conduction electron 4f electron 4f electron 4f and conduction electrons form a spin-singlet state. The interplay between two 4f electrons mediated by conduction electrons (RKKY:Rudermann-Kittel-Kasuya-Yoshida) Magnetic Order Fermi Liquid heavy fermion system : 重い電子系

  25. field dependence of the resistivity at 1 bar μ0H < 3 T μ0H > 3 T Tmax⇒ no change Tmax⇒ toward lower temperature suppress spin fluctuation

  26. Kondo interaction strength(CK) CK decreases with P Ck: Kondo interaction strength

  27. P dependence of CK CK ~ J3N(EF)2 J : hybridization N(EF) : density of states at Fermi level P enhances J but N(EF) strongly diminishes Ck: Kondo interaction strength CK decreases with P CK decreases

More Related