35 YEARS OF 35 YEARS OF METALLIC SUPERLATTICES METALLIC - PowerPoint PPT Presentation

35 YEARS OF 35 YEARS OF METALLIC SUPERLATTICES METALLIC SUPERLATTICES IEEE DISTINGUISHED LECTURER IEEE DISTINGUISHED LECTURER IVAN K AN K. S SCHULLER LLER DOE DOE NSF, AFOSR, ONR NSF, AFOSR, ONR 1

 IEEE Magnetics Society Home Page: www.ieeemagnetics.org – 3000 full members – 300 student members  The Society – Conference organization (INTERMAG, MMM, TMRC, etc.) – Student support for conferences – Large conference discounts for members – Graduate Student Summer Schools – Local chapter activities – Distinguished lectures  IEEE Transactions on Magnetics – ~2000 peer reviewed pages each year – Electronic access to all IEEE Transactions on Magnetics papers  Online applications for IEEE membership: www.ieee.org/join – 360,000 members – IEEE student membership IEEE full membership

The Journal of Your Field  Peer reviewed  Rapid publication  IEEE Xplore archive  Worldwide circulation  Four ‐ page articles  No page charges On line at ieeexplore.ieee.org Submit manuscripts at mc.manuscriptcentral.com/maglet ‐ ieee

Thank you 4

What WE think of Science

What the rest of the world thinks • Boooooooooring !!!!!!! • That Is The Subject I Never Understood In High School (College) • You Must Be Very Intelligent 6

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8 MOST DON’T DO THIS Small Bangs Big Bangs Bangs

FASCINATING PHYSICS USEFUL YOU YOU USE IT MILLIONS OF TIMES A DAY 9

10 WHY PHYSICS WHY PHYSICS

My St My Star art 58 YEARS A 58 YEARS AGO 19 1957 Cluj, K Cluj, Kolozsv olozsvar ar, Clausenbur , Clausenburg 11

Lucky to Liv Live in Chile Danny, Jonny, Jackie, Oceanographer Physicist Teacher “Life need not be easy, provided only that it is not empty.” 12 Lise Meitner

Lucky to Study tudy in Chile 13

SOMETHING FROM NOTHING SOMETHING FROM NOTHING • Noether’s theorem  Conservation laws from philosophy • Ginzburg-Landau 2 nd order phase transition  Superconductivity, magnetism ……………………. from series expansion Ask fundamental questions 14

15 CONSERVATION LAWS CONSERVATION LAWS SYMMETRY SYMMETRY AND AND Noether her Emmy N Emm

Landau-Ginzbur Landau-Ginzburg meter :  Order P Order Parameter Superconducting Gap, Magnetization, Distorsion , TAYLOR EXPANSION TAYLOR EXPANSION 16

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CRITIC CRITICAL SL AL SLOWIN ING DO G DOWN WN me (nsec) (nsec) tion Time Relaxation T Relaxa TEMPERA TEMPERATURE URE I. K. Schuller and K. E. Gray, PRL36, 429(1976) 19

Many Young Friends Many Young Friends 20

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Wh Why do Ph y do Physics ics • Univ Univer ersal beha sal behavior vior  Power Laws • Ne New P Parameters rs Range  Smaller • We Weird B Behavior  Separate Charge and Spin • Big Que Big Questions tions  What is intelligence 22

Wh Why do Ph y do Physics ics • Univ Univer ersal beha sal behavior vior  Power Laws • Ne New P Parameters rs Range  Smaller • We Weird B Behavior  Separate Charge and Spin • Big Que Big Questions tions  What is intelligence 23

Metal-Insulator Transition VO VO 2 24 Z. Yang, C. Ko, and S. Ramanathan, Annu. Rev. Mater. Res. 41 (2011) 24

Nano-sca Na cale V VO 2 200 nm R 4 10 3 10 R (  ) 2 10 1 10 310 320 330 340 350 360 T (K) 4 10 6 R (  ) 4 R (k  ) 3 10 Multiple jumps 2 across the metal- 2 10 insulator transition 338 339 340 341 342 25 339 340 341 342 T (K) T (K)

26 ale Invariance riance Scale Inv Sc 26

Statistics of Jumps 4 10 2000 100 cycles Number of Jumps Number of Jumps 3 10 1500 1000 2 10 500 1 10  = 2.48  0.05 0 40 80 120 0 Jump Size (  10 1 2 3 10 10 10 Jump size (  ) Power law: p(A)  A -  p -probability A - jump size 27

Avalanches • Triggered and develops • Many Small avalanches • A few big ones 28

29 UNIVERSALITY UNIVERSALITY PHYSICS PHYSICS OF OF

Power Laws Earthquake Magnitude  = 1.2 Citations (I.K. Schuller) JP. Sethna et al ., Nature 410, 242 (2001) 100 Connectivity of Internet Number of Papers  = 1.7  = 2.1 10 1 10 100 1000 30 Number of Citations M. Newman Phys. Today, P. 33 Nov. 2008

Avalanches with Power Laws Barkhausen Noise Plasma Burst (sun)  ~1.3  ~2.0 Martensites Sand Piles  ~2.4 31  ~1 - 3, depends on sand

Wh Why do Ph y do Physics ics • Univ Univer ersal beha sal behavior vior  Power Laws • Ne New P Parameters rs Range  Smaller • We Weird B Behavior  Separate Charge and Spin • Big Que Big Questions tions  What is intelligence 32

CHARACTERISTIC LENGTH SCALES CHARACTERISTIC LENGTH SCALES Nano Nano science science Chemistr Chemistry Phy Physics ics 33

NanoBio French Theorist Un homme de six pieds fait Un homme de six pieds fait Francois-Marie Arouet sur la terre la meme figure sur la terre la meme figure precisement que fait sur une precisement que fait sur une boule de quatre pieds de boule de quatre pieds de circonference un animal qui circonference un animal qui serait a cette circonference serait a cette circonference de roue comme de roue comme 1 est a 91 500 000 1 est a 91 500 000 ~10nm Merci Andre Magnan NANO VOLTAIRE NANO VOLT President Soc. Voltaire 34 KVAB, U. de Nanterre

35 SCIENCE DRIVEN RESEARCH I.K.Schuller, Phys.Rev.Lett. 44, 1597(1980)

36 MAGNETO-TRANSPORT MAGNETO-TRANSPORT

~ 20 % MR ~ 20 % MR Giant MagnetoResistance- GMR 37

38 In 4 or 5 years, this will be THE field in materials science. April, 1981

2007 PHYSICS NOBEL Grunberg Grunberg Fert Fert GIANT MAGNETORESISTANCE GMR 39

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GMR GMR SPIN SPIN EXCHANGE EXCHANGE TORQUE TORQUE BIAS BIAS I 1 H FC (kOe) SCIENCE SCIENCE 0.5 2.0 State: +1 5.0 M / M S 0 Cu State: 0 State: -1 Co -1 -4 -3 -2 -1 0 1 2 3 4 H (kOe) APPLICATIONS APPLICATIONS U C T ) T E Hard disk drives Sensors 41 MRAM

Nanoscience (when things get small) TunnelSchroedv8_1-desktop.m4v 42

Spin-electronics 43 Spintronics or magnetism electronics charge e - spin electron

Basic Research=Transformative Technology 44

Wh Why do Ph y do Physics ics • Univ Univer ersal beha sal behavior vior  Power Laws • Ne New P Parameters rs Range  Smaller • We Weird B Behavior  Separate Charge and Spin • Big Que Big Questions tions  What is intelligence 45

THE REAL THE REAL CHESHIRE CAT CHESHIRE CAT Went awa nt away and and left behind his smile left behind his smile 46

A Crazy experiment A Crazy experiment NON-LOCAL SPIN VALVE FM FM I V FM: ferromagnetic I NM: non-magnetic NM Decouple Decouple SPIN curr SPIN om CHAR CHARGE GE curr current fr ent from current ent 47 Valenzuela et al.,PRL 94 , 196601 (2005)

Sample Photolithography + Au contacts 1µm FM FM NM Py/Cu/Py Co/Al/Co 0.5µm 48

Non-local spin valve effect 1.0 1.0 1.0 1.0 I=0.5 mA I=0.5 mA I=0.5 mA I=0.5 mA •Bipolar switching 0.8 0.8 0.8 0.8 • Spin signal: 0.6 0.6 0.6 0.6  P  0.4 0.4 0.4 0.4 V V V  AP 0.2 0.2 0.2 0.2 I I V/| I |(m  ) V/| I |(m  ) V/| I |(m  ) V/| I |(m  ) 0.0 0.0 0.0 0.0 •Memory effect -0.2 -0.2 -0.2 -0.2 -0.4 -0.4 -0.4 -0.4 -0.6 -0.6 -0.6 -0.6 -0.8 -0.8 -0.8 -0.8 Py/Cu/Py Py/Cu/Py Py/Cu/Py Py/Cu/Py T=4.2 K T=4.2 K T=4.2 K T=4.2 K -1.0 -1.0 -1.0 -1.0 -800 -800 -600 -600 -400 -400 -200 -200 0 0 200 200 400 400 600 600 800 800 -800 -800 -600 -600 -400 -400 -200 -200 0 0 200 200 400 400 600 600 800 800 H (Oe) H (Oe) H (Oe) H (Oe) 49

Spintronics: applications Giant magnetoresistance (GMR) Magnetoresistive read head Discovery: 1988 Market: IBM 1997 Tunnel magnetoresistance (TMR) Magnetic RAM 4 Mbit chip Revisited: 1995 Demo: Motorola 2003 Market: Freescale 2006 50

Wh Why do Ph y do Physics ics • Univ Univer ersal beha sal behavior vior  Power Laws • Ne New P Parameters rs Range  Smaller • We Weird B Behavior  Separate Charge and Spin • Big Que Big Questions tions  What is intelligence 51

$ 30,000 $ 200,000,000 Jonathan Schuller 11,968 processors, 6 months old 12 Terabytes memory, 600 Terabytes disk storage 52

Unifying Principles for Intelligence ? Imitate Nature “Biologically Inspired” 53

54 Sensors processor Local PROCESSOR CENTRAL Sensors processor Local

55 processor Sensors Feedback Local PROCESSOR CENTRAL Nanoscience Communications processor Sensors Local Wireless

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IMPLEMENTATION Reduce to practice Imitate nature FUNDING FUNDING 57

What is needed • Expertise- physicists, chemists, biologists, engineers • Techniques-Nanoscience, Materials, Wireless,Engineering • High Tech Facilities • Various implementations • Interactions • Steady Support 58