Spin Circuits: Bridge from Science to Devices

Transcription

1 Spin Circuits: Bridge from Science to Devices Spin Circuits Generation of spin potentials Propagation of spin potentials Building spin circuits What is the potential? Why electrons flow Q & A Forum * Transport theories Where does the potential drop?

2 Source Channel 1 10 ohms 100 ohms E.7.9 Magnetic contacts Fe 26 1s 2 2s 2 2p 6 3s 2 3p 6 3d 6 4s 2 D(E)

3 Source Channel Drain GMR 10 ohms E 100 ohms 100 ohm 10 ohms D(E) Define 2-component with 2x2 G-matrix V, I

4 Charge-spin Charge Spin

5 Channel 4x4 G-matrix

6 Channel G-matrix rotation

7 Channel Angular MR EXPERIMENT Urazhdin et al. PRB 2005 R (n-ohms) R P R AP R (n-ohms) a=2.8 P=0.33 Camsari et al. unpublished

8 Channel It is NOT obvious!! MTJ SV Insulator R (n-ohms) a=2.8 P=0.33 Camsari et al. unpublished

9 Channel Key Point Spin circuit model can give EXACT same result as Boltzmann But it requires the use of 4-component currents and voltages Spin potential 0

10 Channel Moving on. FM FM Spin Circuits Generation of spin potentials Propagation of spin potentials Building spin circuits What is the potential? Why electrons flow Transport theories Where does the potential drop?

11 Channel Spin Diffusion FM FM Charge up Spin Spin flip dn

12 Channel G-matrix for Diffusion FM FM Charge component = 0 c z x y

13 Local Non-local spin valve I V in V Nonlocal I µ up No current µ dn Srinivasan et al. Book Chapter, available on condmat

14 Polarizer & Analyzer V in V Nonlocal I µ up No current µ dn P AP

15 I I FM GSHE TI I s I GSHE Charge Flow 1-2 I 1 2 Spin Flow V s FM ISHE 4

16 EXPERIMENT: Otani et al. PRL (2012) ISHE SPIN CIRCUIT THEORY Camsari et al. (unpublished) V

17 Vector Spinor Increased current Quantum mysteries V I No current Without middle magnet FM FM FM I

18 up dn N 2N Key Point Spin circuit models seem to capture the physics of generation, propagation and detection of spin signals: both collinear & non-collinear 4N components NEGF teats entire device as a giant spin 4N 2 components

19 Moving on. What is the potential? Why electrons flow Transport theories Where does the potential drop? Spin Circuits Generation of spin potentials Propagation of spin potentials Building spin circuits Nanomagnet Dynamics H Dr. Sun, IBM AFTERNOON

20 Experiment: Multiple groups GSHE driven MTJ MTJ I s MTJ From Ralph et al. Science 2012 I s I

21 I MTJ Spin Switch Input & Output electrically isolated Gain & Directivity Can be used to build circuits CMOS Inverter MTJ Information propagated magnetically APL 101, (2012) Zhihong Chen Joerg Appenzeller

22 Spin Switch: Circuit model V MTJ I out Dipolar Couplin g I in

23 Energy-Delay Product V I out Dipolar Couplin g I in

24 Spin-orbit coupling Behin-Aein et al. APL 2011 I I I Spin-orbit coupling TI?? VCMA??

25 From Science to Devices & Circuits Spin Switch V Memory Boolean Logic FM Insulator Neuromorphic: Diep et al. Quantum Logic: Sutton et al. I in I out Dipolar Couplin g T I VCMA

26 Thank you!! Spin Switch Spin transport physics circuits with 4-component voltages & currents V Spin circuits multi-physics framework for integrating new phenomena New physics being discovered regularly, but the ultimate device is yet to be invented I out Dipolar Couplin g I in Q & A Forum: Under construction *

27 Kerem Camsari Vinh Diep Rafatul Faria Samiran Ganguly Seokmin Hong Shehrin Sayed Kuntal Roy Brian Sutton Spin circuit based modular approach Devices and circuits with spin switches Spin circuits with SPICE GSHE and TI VCMA Quantum Computing Acknowledgements Spin Switch Joerg Appenzeller Zhihong Chen Suprem Das Chia Ching Lin Ashish Penumatcha Q & A Forum: Under construction *