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P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Superconductivity 101 A Primer for Engineers Paul M. Grant

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Presentation on theme: "P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Superconductivity 101 A Primer for Engineers Paul M. Grant"— Presentation transcript:

1 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Superconductivity 101 A Primer for Engineers Paul M. Grant pgrant@epri.com www.epri.com/staff_papers/sst

2 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Fathers of Electricity Discoverers

3 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Fathers of Electricity Practitioners

4 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Fathers of Cryogenics DewarKammerlingh-Onnes CH 4 112 K O 90 N 2 77 Ne 27 H 2 20 He 4.2

5 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 ( ( ( Models of Electrical Conductivity The First Idea: R T Just Goes to Zero! ((( ( ( ( ( ( ( e-e- e-e-

6 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 The Most Popular: R T Freezes Out! e-e- Models of Electrical Conductivity

7 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Models of Electrical Conductivity Reality: R T Limited by Impurities!  e-e-

8 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Thus the mercury at 4.2 K has entered a new state, which, owing to its particular electrical properties, can be called the state of superconductivity H. Kamerlingh-Onnes (1911) 1911 A Big Surprise!

9 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Magnetic Properties 0 -1/4   T H off H on 0 -1/4   T H on Expected (Lenz’ Law) Weird ! (Meissner Effect)

10 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 They all tried… and failed!

11 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 They came close... Fritz London Lev Landau Irwin Froehlich “The B-field does penetrate.” E ~ 2 dJ/dt, B ~ 2  J “Since SC is a second-order phase transition, there must be an order parameter involved.” “T C depends on the mass of the atoms (isotope effect), so the SC must be tied to lattice vibrations (phonons).”

12 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 They Got It Right! B ----- C ----- S Bardeen: “It’s a macroscopic quantum state” Cooper: “It’s got twice the charge you’d expect” Schrieffer: “  ’s a statistical wavefunction” There has to be a regime where the lattice vibrations act to bind electrons together rather than scatter them with loss as given by Ohm’s Law.

13 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Physics of Superconductivity ++ ++ e-e- e-e- Electrons Pair Off! BCS Equation

14 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 “Cooper’s Problem”

15 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Important Numbers in Superconductivity Transition Temperature, T C Way below 300 K Critical Current Density, J C 10 -2 - 10 6 A/cm 2 Critical Magnetic Field, H C 10 -4 - 10 T London Penetration Depth, 10 - >1000 Å Pippard Coherence Length,  10 - >1000 Å G-L Parameter,  = /  0.01 - 100 NB! All these numbers depend on each other. E.g., H C ~ 

16 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 T C vs. Year: 1911 - 1980 Year 0 5 10 15 20 25 190019101920193019401950196019701980 Temperature (K) Hg Pb NbN V 3 Si Nb 3 Sn Nb 3 Ge Cubic Metals

17 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 MRI & “Big Physics” Magnetic Resonance Imaging Philips Tevatron Fermi National Laboratory

18 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 1986 Another Big Surprise! Bednorz and Mueller IBM Zuerich, 1986 Onset T C = 40 K !

19 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 1987 “The Prize!”

20 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 March 3, 1987 “123” Discovered

21 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Woodstock of Physics NYC, 1987 Physicists’ Night Out!

22 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Y-123Bi-2223 HTS Layered Perovskites

23 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 T C vs. Year: 1911 - 1999 190019201940196019802000 0 50 100 150 200 Temperature, T C (K) Year Low-T C High-T C 164 K

24 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 HTSC Phase Diagram

25 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 HTS Theories Phil Anderson “It can’t be just an accident that high temperature superconductivity occurs in a host material whose insulating state is an antiferromagnet, and, which when doped with holes to a level where magnetic behavior disappears, we get superconductivity.” Current Situation: The pair coupling is believed to be magnetically mediated. The normal conducting state is believed not to be a Landau liquid. The superconducting state is domain- like, occurring as electronic “stripes.” However, there is yet no generally accepted model today!

26 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Boson Flavors

27 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Ultimate Boson Put-ons!

28 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 GLAG Lev Gor’kov

29 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Irreversibility Line Mixed Normal H C2 Magnetic Field TCTC Temperature H C2 1/4  Type II Superconductivity Mixed H C2 Meissner H C1 H C2 Normal

30 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Abrikosov Vortex Lattice Dipole Force F Lorentz J H Type II Superconductor in the Mixed State

31 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Hg-1212: Fission-Induced Defects L. Krusin-Elbaum, et al., Nature World record H irr at 77 K in Hg-1212 Hg-1212 Prototype Tapes made at TCSUH Potential for high- field magnet inserts

32 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Extrinsic Pinning 10  m  m DECORATED VORTEX ARRAYS with random heavy ion tracks clean M. Leghissa, et al. Phys. Rev.B48, 1341 (1993)

33 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Vortex Matter Static Phase Diagram Temperature Magnetic Field Dynamic Phase Diagram TCTC H C2 H C1 F Lorentz Elastic Flow Plastic Flow Liquid Flow Normal Liquid Glass Solid Bose Glass Polymer Glass Melting Line Meissner State SC Fluctuation Regime

34 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 J C (B,T) for BSCCO

35 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 BSCCO OPIT/Ag E-J Characteristic E = aJ n n = 15 T = 77 K E = 1  V/cm

36 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Solenoid Loop Current: t > t 0 L R(I) I(t) bIL dI dt 0 I(t) b(n1) L (tt)I n 00 1n 1 1n            

37 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 “Persistent” Current Decay B = 0.50 T B = 0.25 T 12 Days

38 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Type II Hysteresis H M

39 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Hysteretic ac Loss

40 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 The Future 2028

41 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 The Future 700 K ! May, 2028

42 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 Electricity: A Life Necessity California, Summer 1996 Quebec, Winter 1997

43 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 “You can’t always get what you want…”

44 P. M. Grant Superconductivity 101 Superconductivity Workshop Charlotte, 24 May 1999 “…you get what you need!”


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