Los Alamos National Lab Filip Ronning Operated by Los Alamos - - PowerPoint PPT Presentation

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Los Alamos National Lab Filip Ronning Operated by Los Alamos - - PowerPoint PPT Presentation

May 07, 2023 127 likes •411 views

The 115 Superconductors Eric Bauer Fedor Balakirev Xin Lu Marc Janoschek Roman Movshovich Joe Thompson Vladamir Sidorov Jianxin Zhu (LANL) Soonbeom Seo Tuson Park (SKKU) Zach Fisk (UC Irvine) Philip Moll (ETH) Hiro Sakai (JAEA)

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SLIDE 1

Operated by Los Alamos National Security, LLC for NNSA

The “115” Superconductors Filip Ronning

Los Alamos National Lab

Eric Bauer Fedor Balakirev Xin Lu Marc Janoschek Roman Movshovich Joe Thompson Vladamir Sidorov Jianxin Zhu (LANL) Soonbeom Seo Tuson Park (SKKU) Zach Fisk (UC Irvine) Philip Moll (ETH) Hiro Sakai (JAEA) Hiroshi Yasuoka (JAEA) Luis Balicas (NHMFL)

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SLIDE 2

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  • 115 heavy fermion primer
  • Non-universality of dopants (Cd vs. Sn doping)
  • Influence on quantum criticality and superconductivity
  • High Magnetic Field Study of CeRhIn5
  • Competing Density wave
  • Gigantic anisotropy

Outline:

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SLIDE 3

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Superconductivity in Heavy Fermions

2 4 6 8 10 0.0 0.5 1.0 1.5 2.0

C/T (J/mol-K2) T (K)

CeCoIn5 H=0 T CeCoIn5 H=9 T LaCoIn5

*

m T C ∝

  • Heavy

Electrons

  • Large entropy goes

into the SC state

  • Nodal QP’s
  • that are heavy
  • Stoichiometric → high purity,

large m.f.p. (> 1µm)

  • small energy

scale → highly tunable

  • Tc/TF similar to cuprates
  • Dirac

Materials

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SLIDE 4

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SC in proximity to Antiferromagnetism

Monthoux , Pines, & Lonzarich, Nature ‘07

CeCoIn5

  • Parent compound is an AF metal
  • Tc/TF ~ 0.1
  • SC is unconventional (power laws/sign changing OP)
  • Tunable with doping or pressure.
  • Spin Fluctuations…
  • Phase diagram generic for Cerium heavy fermion SC’s

Nandi, Canfield, et al, PRL ‘10

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SLIDE 5

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Reducing ¡Dimensionality ¡ Increasing ¡Bandwidth ¡

CeIn3 CeMIn5 PuMGa5 Ce2MIn8

Tc = 0.2 K Tc = 2.1 K Tc = 18.5 K Tc = 2.3 K

13 compounds in this family are superconductors

NpPd5Al2

Tc = 5 K

CeM2In7

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SLIDE 6

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Cd d vs Sn n doping doping in in the he 115’ 115’s

A Tale ale of

  • f Two
  • Dopant
  • pants

Why doping? Dopants provides a window into novel states of matter

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SLIDE 7

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0.0 0.5 1.0 1.5 2.0 2.5 1 2 3 4 5

Tc TN SC AFM+ SC AFM

T (K) P (GPa)

Cd doping ~ <decreases hybridization>

How we identified the instability in CeCoIn5

CeRhIn5

~ CeCoIn5

  • H. Hegger, et al. PRL (2000); L. Pham, et al. PRL (2006); E.D. Bauer, et al. PRB (2006)

Sn doping ~ <increases hybridization>

CeRhIn5 (P) CeRh(In,Sn)5 (P) CeCo(In,Cd)5 (P)

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SLIDE 8

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Cd versus Sn doping

CeRhIn5 CeRh(In,Sn)5 CeCo(In,Cd)5

  • T. Park, et al. Nature ’08
  • S. Seo, et al. Nat. Comm. ’15
  • S. Seo, et al. Nat. Phys. ’13

0.0 1.0 2.0 10 100 Pc1

Temperature (K) Pressure (GPa)

0.900 1.45 2.00

Tmax SC AFM

ρ(P)/ρ(2.46)

0.0 1.0 2.0 1 2 3 4 5 Pc1

T (K) P (GPa)

AFM

SC

AFM SC

CeCo(In,Cd)5

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SLIDE 9

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Cd doping:

§ Decreased hybridization § Small Tc suppression § Signature of QCP disappears.

Sn doping:

§ Increased hybridization § Larger Tc suppression § Signature of QCP remains.

Cd versus Sn doping

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SLIDE 10

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A(Bulk) B C D Cd = “AFM droplets” Sn ≈ homogeneous

NMR

  • H. Sakai, et al. unpublished
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SLIDE 11

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Little doubt that this system is dx2-y2. Robustness likely due to strong coupling and extreme multiband. Are inhomogeneous dopants less pair-breaking than homogeneous ones? Are filled shells less pair breaking (ie. Cd and Zn)? Inhomogeneity can obscure signatures of criticality!

  • K. Gofryk, et al PRL ‘12

Robustness to impurity scattering: CeCoIn5

ξ0/l 0.4 0.26 0.1

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SLIDE 12

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v QC not always so apparent in pnictides

(QC scaling removed by disorder?)

v SC still robust.

  • F. Ning, T. Imai, et al. JPSJ ‘09

Quantum Criticality in Pnictides

Ba(Fe,Co)2As2 BaFe2(As,P)2

  • K. Hashimoto, et al. Science ‘10
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SLIDE 13

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Acces ccessing ing the he AFM FM QC QCP wit ith h ma magnet gnetic ic field ield

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SLIDE 14

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Phase boundaries from T. Park, NJP (2009) and L. Jiao, et al. PNAS (2015)

A field induced density wave in CeRhIn5

  • P. Moll, et al. Nat. Comm. (in press)
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SLIDE 15

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Microstructured CeRhIn5

  • P. Moll, et al. Nat. Comm. (in press)

50 um

v Enables magnetoresistance at high fields v High current densities possible v Transport anisotropy of small crystals

RRR ~ 260

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SLIDE 16

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A field induced density wave in CeRhIn5

v Field induced transition within the AFM state v Hysteresis vanishes in pulsed fields.

  • P. Moll, et al. Nat. Comm. (in press)
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SLIDE 17

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A field induced density wave in CeRhIn5

  • P. Moll, et al. Nat. Comm. (in press)

v Not clearly observed in M(H) or Rc(H) v Small fraction of the Fermi surface participates

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SLIDE 18

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A field induced density wave in CeRhIn5

  • P. Moll, et al. Nat. Comm. (in press)

v I-V curves resemble CDW systems

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SLIDE 19

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Angular dependence of the density wave state

  • P. Moll, et al. Nat. Comm. (in press)

v Pushing field into the ab-plane makes the

density wave formation energetically unfavorable.

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SLIDE 20

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Fermi surface topology change

  • P. Moll, et al. Nat. Comm. (in press)
  • L. Jiao, et al. PNAS (2015)
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SLIDE 21

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Compet

  • mpeting

ing Phas hases es

  • B. Keimer, et al.

ArXiv: 1409.4673

A field induced density wave

Similarity with cuprates

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SLIDE 22

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Anomalous transport with H//ab

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SLIDE 23

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Spin Waves in CeRhIn5

The ¡existence ¡of ¡a ¡spin ¡gap, ¡ ¡ Δsg ¡= ¡0.25 ¡meV, ¡is ¡ unexpected ¡for ¡the ¡ordered ¡ Q ¡= ¡(½, ¡½, ¡0.297) ¡moments. ¡ J0= ¡0.37 ¡meV, ¡ ¡ J1 ¡= ¡0.05 ¡meV ¡ J2 ¡= ¡0.809 ¡J1

¡

Δ ¡= ¡0.82 ¡

CeRhIn5 is a frustrated system along the c-axis

  • P. Das, et al. PRL (2014)
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SLIDE 24

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Spin-Or pin-Orbit bit Coupling

  • upling
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SLIDE 25

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How does Spin-Orbit coupling influence Tc?

2.5 2.0 1.5 1.0 0.5 0.0

Max Tc Z

4/n

3 ~ λSO

Co Rh Ir

CeMIn5

  • Y. Chen, et al. (unpublished)
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SLIDE 26

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Summary ¡

two non-magnetic dopants (Cd and Sn) produce dramatically

different responses.

Inhomogeneity can have weaker pair breaking effects Can also disguise signatures of quantum criticality Field Induced Density Wave in CeRhIn5 under applied magnetic

field

How does spin-orbit coupling influence Tc?

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SLIDE 27

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