Spin(calori)tronics = spin+heat+electronics

Transcription

1 Spi(calori)troic = pi+hat+lctroic Grrit aur Sdai 仙台 Populatio:.046 illio Grrit E.W. aur Grrit aur Tohoku Uivrity ( 東北 学 ) Udrgraduat,094 Potgraduat 7,704 itratioal tudt,346 ctur DC Magtolctroic i. dfiitio ii. quatu chaic of pi iii. chag ad agti iv. pi traport i pi valv v. pi trafr torqu AC Magtolctroic 3 Spi Caloritroic Dfiitio Elctroic: Spitroic: Spi caloritroic: Cotrol of charg currt i all circuit ad dvic Gratio, dtctio, ad cotrol of charg ad pi currt Charg, pi, rgy ad tropy currt Elctroic i traport of charg Oh aw j V A V Gl V GV A R A G V E j E A A P V R G S h Grrit E.W. aur iar rpo of hat ad a traport: Fourir/Fick aw

2 Spi i agular otu Magtic ot i pi v Grrit E.W. aur M Ka & Schr 969 d r M V r v claical gyroagtic ratio Magtic dipol i a agtic fild Macropi U M T M Ergy Torqu d dt F d M M dt M - d dt T M dm d T M dt dt adau-ifhit quatio F M Forc piig top i gravity fild agtic ot i agtic fild Wolgag Pauli ad Nil ohr Elctro pi ad quatu chaic Wolfgag Pauli, yi, S 0 0 Tipp top Wikipdia 0 S 3

3 Elctro pi vctor oprator σ μg g ohr agto σ g 0 0 i 0 σ,, Pauli atric 0 i 0 0 ˆ g 0 0 H μ H 0 Rotatio i quatu chaic ˆ f f R d f, y f d, y dy f d dy y i f y fd ˆ d f y y (, y,0) d yd y y dy y d Fiit rotatio: li d ˆ i R ˆ li d log li log li ˆ i ˆ i logr li d ˆ ˆ R i ˆ Rotatio i quatu chaic Rotatio of a tat by a agl aroud a ai with uit vctor : R Rotatio oprator: ˆ R p i ˆ / Elctro pi: ˆ σ ˆ R y With co,i,0, R, 0 grat all poibl pi tat. Eapl: R, 0 ˆ R i σ / Spi o th loch phr R 0 / i y / 0 0, 0! 0 Chck: co i i co Spi-up tat i -dirctio i obtaid by rotatio about y-ai with.,0,0 0 R, 0 May-body probl ditiguihability ad Pauli cluio Prutatio atiytry:, 0 r, r r, r r, r 0 r r Two lctro caot b i th a tat or at th a pi ad otu coordiat. P r r r r,,, chag hol r r 3

4 Echag itractio rducd Coulob rpulio du to chag hol E Coul C r r M icrad kitic rgy by lctro cofit du to Hibrg ucrtaity rlatio p / p E ki M M r C avrag ditac btw lctro lctro ffctiv a Th pi-paralll (=frroagtic) tat i favorabl wh th kitic rgy cot du to Pauli pricipl i allr tha th Coulob rgy gai, i.. wh M * ad/or r ar larg. Thi rgy gai i calld chag itractio. Stor tallic frroagt : chag(-corrlatio) pottial that rflct th rgy plittig btw ajory ad iority pi tat. E F p F p F p y p Spi-dpdt diti, Fri Halftallic ota, frroagt ad obiliti Ab iitio bad tructur calculatio FCC-Co Hud rul ad uprchag F 3+, M + :3d 5 ad S=5/ uprchag: atifrroagtic couplig through filld hll Zwirycki, Xia, t al. (008) Yttriu ro Gart Y 3 (3+) F (3+) (F (3+) O 4 (-) ) 3 A.R. Chakhouradia - ot foud i atur - 80 ato/priitiv uit cll - frriagtic iulator - Curi tpratur 550 K - Gilbrt dapig ~0-5 4

5 ilayr ad pi valv Prpdicular aotructur crytalli aorphou MgO CoF Oid MgO tul barrir o th atoic cal TEM iag of a full dvic Appl. Phy. tt. 95, 39 (009) J. Appl. Phy. 05, (009) atral aotructur Spi-dpdt itrfac traiivity Atta 50 Py Cu pi valv Co Cu va W Co graph pi valv ajority iority Spi accuulatio ad pi currt F N c F N F pi valv d N d D f N d D f pi-flip diffuio lgth diffuio cotat pi-flip rlaatio ti V V V V 5

6 F N F pi valv F N F pi valv d d V V V V F N F pi valv: o-colliar d Slocwki torqu i half tal Noral / HMF / / logitudial pi currt travr pi currt = torqu = / /?????? N V V N = ubr of icoig chal Switchig by pi trafr Switchig by pi trafr 6