The Spin Torque Lego from spin torque nano-devices to advanced - PowerPoint PPT Presentation

The Spin Torque Lego from spin torque nano-devices to advanced computing architectures J. Grollier et al., CNRS/Thales, France NanoBrain

Spintronics : roadmap Magnetic Giant Magneto-Resistance - 1988 Nanostructures reading the magnetization configuration sensors HDD read heads Spin Transfer - 1996 writing the magnetization configuration J. Slonczewski JMMM 1996 L. Berger PRB 1996 julie.grollier.free.fr ISAMMA 2013 1

Spintronics : roadmap Magnetic Giant Magneto-Resistance - 1988 Nanostructures reading the magnetization configuration sensors New devices HDD read heads - digital memories - nano-oscillators Spin Transfer - 1996 - memristors writing the magnetization configuration J. Slonczewski JMMM 1996 L. Berger PRB 1996 julie.grollier.free.fr ISAMMA 2013 1

Spintronics : roadmap Magnetic Giant Magneto-Resistance - 1988 Nanostructures reading the magnetization configuration sensors New New devices Computing HDD read heads - digital memories Architectures - nano-oscillators Spin Transfer - 1996 ? - memristors writing the magnetization configuration J. Slonczewski JMMM 1996 L. Berger PRB 1996 julie.grollier.free.fr ISAMMA 2013 1

Principle of spin-torque devices R I(t) m spin magneto- torque resistance t , ns magnetization resistance dynamics variations julie.grollier.free.fr ISAMMA 2013 2

Principle of spin-torque devices R I(t) m spin magneto- torque resistance t , ns magnetization resistance dynamics variations T IP T OOP + spin torque = in-plane torque out-of-plane torque 2 torques  2 knobs to engineer the dynamic response julie.grollier.free.fr ISAMMA 2013 2

In-plane versus out-of-plane torques H M fixed T damping T field eq. position M free julie.grollier.free.fr ISAMMA 2013 3

In-plane versus out-of-plane torques E T IP in-plane torque  anti-damping H M fixed P AP T damping destabilizes magnetization T field T IP eq. position M free julie.grollier.free.fr ISAMMA 2013 3

In-plane versus out-of-plane torques E T IP in-plane torque  anti-damping H M fixed P AP T damping destabilizes magnetization T field T IP position T OOP eq. E M free H OOP out-of-plane torque  field-like torque P AP modifies energy barrier julie.grollier.free.fr ISAMMA 2013 3

In-plane versus out-of-plane torques E T IP in-plane torque  anti-damping T IP P AP destabilizes magnetization Magnetization dynamics with the in-plane torque  3 scenarios depending on H julie.grollier.free.fr ISAMMA 2013 3

Binary Memory H < H c E STT P AP Hysteretic Switching 400 350 AP Resistance (  ) 300 250 P 200 150 -2 -1 0 1 2 d.c. current (mA) julie.grollier.free.fr ISAMMA 2013 4

Binary Memory H < H c E First observations : STT Katine et al. PRL 2000 Grollier et al. APL 2001 P AP Hysteretic Switching Application : STT-MRAM 400 www.everspin.com 350 AP Resistance (  ) FREE LAYER 300 TUNNEL BARRIER FIXED LAYER 250 Isolation transistor OFF P www.nec.co.jp 200 150 -2 -1 0 1 2 target : D-RAM replacement d.c. current (mA) julie.grollier.free.fr ISAMMA 2013 4

Stochastic device H  H c E H STT P AP Telegraphic Switching 340 - 2.7 mA 320 Resistance (  ) 300 340 - 2.9 mA 320 300 0 10 20 30 40 50 60 Time (µs) julie.grollier.free.fr ISAMMA 2013 5

Stochastic device H  H c E First observations : H STT Fabian et al. PRL 2003 Urazhdin et al. PRL 2003 P AP Telegraphic Switching Dwell times controlled by current spin torque = 340 - 2.7 mA 320 Resistance (  ) handle to control 300 probabilities 340 - 2.9 mA 320 : spin dice Fukushima et al. SSDM 2010 300 0 10 20 30 40 50 60  nanoscale random number generators Time (µs) julie.grollier.free.fr ISAMMA 2013 5

Spin Transfer Nano-Oscillators H > H c E H STT P AP Precessionnal state 7 2 ) Power density (nW/GHz/mA 6 5 1.2 mA 4 1.0 mA 3 0.8 mA 2 1 0 2 4 6 frequency (GHz) julie.grollier.free.fr ISAMMA 2013 6

Spin Transfer Nano-Oscillators H > H c E H STT P AP Precessionnal state 7 2 ) Power density (nW/GHz/mA 6 5 1.2 mA 4 1.0 mA 3 0.8 mA 2 1 0 2 4 6 frequency (GHz) julie.grollier.free.fr ISAMMA 2013 6

Spin Transfer Nano-Oscillators H > H c E First observations : H Kiselev et al. Nature 2003 Rippard et al. PRL 2004 STT P AP Precessionnal state ST microwave devices small - work directly at the GHz 7 2 ) Power density (nW/GHz/mA 6 tunable with I and H – radiations proof 5 1.2 mA 4 1.0 mA Applications 3 0.8 mA 2 telecommunication, radars, read heads … 1 0 2 4 6 frequency (GHz) julie.grollier.free.fr ISAMMA 2013 6

Challenges for ST nano-oscillators initial performances: power  100 pW, linewidth  10 MHz Requirements for applications: - Power > 1 µW - Linewidth < 1 KHz julie.grollier.free.fr ISAMMA 2013 7

Challenges for ST nano-oscillators initial performances: power  100 pW, linewidth  10 MHz Requirements for applications: - Power > 1 µW : P  D R 2  high TMR MgO based MTJs   - Linewidth < 1 KHz julie.grollier.free.fr ISAMMA 2013 7

Challenges for ST nano-oscillators initial performances: power  100 pW, linewidth  10 MHz Requirements for applications: - Power > 1 µW : P  D R 2  high TMR MgO based MTJs   - Linewidth < 1 KHz   julie.grollier.free.fr ISAMMA 2013 7

Strategies to decrease LW • 1 st source of LW : • 2 d source of LW : T  0 mode hopping (freq. spread) phase/amplitude noise Tiberkevich et al, PRB 2008 julie.grollier.free.fr ISAMMA 2013 8

Strategies to decrease LW • 1 st source of LW : • 2 d source of LW : mode hopping (freq. spread) phase/amplitude noise work with a dynamic mode well Tiberkevich et al, PRB 2008 separated in energy from other modes  Vortex gyrotropic mode P = 0.6 µW LW = 590 kHz A. Dussaux , JG et al ., Nature Com. 2010 julie.grollier.free.fr ISAMMA 2013 8

Strategies to decrease LW • 1 st source of LW : • 2 d source of LW : mode hopping (freq. spread) phase/amplitude noise work with a dynamic mode well rigidify the phase separated in energy from other modes  Vortex gyrotropic mode  Synchronization P = 0.6 µW LW = 590 kHz B. Georges , JG et al ., PRL 2008 A. Dussaux , JG et al ., Nature Com. 2010 A. Dussaux, JG et al, APL 2011 julie.grollier.free.fr ISAMMA 2013 8

Microwave oscillator I R V stt m I dc ST MR V=RI t t t stt dc current sustained precession resistance osc. ac voltage 40 20 Voltage (µV) 0 -20 -40 0 20 40 Time (ns)  strong advances towards applications julie.grollier.free.fr ISAMMA 2013 9

Spin wave emitter I stt m I dc ST exch. inter. t stt dc current local sustained precession spin wave emission Tsoi et al. PRL 1998 Demidov et al. Nat. Mat. 2010, Madami et al., Nat. Nano. 2011 Applications: Magnonics (computing with spin waves) julie.grollier.free.fr ISAMMA 2013 10

Microwave detector stt I>0 m I R V I dc ST MR V=RI stt I<0 t t t resonance if w = w 0 ac current resistance osc. dc voltage Tulapurkar et al. Nature 2005 - Ishibashi et al. APEX 2010 140 120 Spin torque diode d.c. voltage (µV) 100 80  250 mV/mW diode sensitivity = V diode / P rf 60 40  sensitivity of the schottky diode at RT 20 0 3.5 4.0 4.5 5.0 5.5 Frequency (GHz) julie.grollier.free.fr ISAMMA 2013 11

Lego bricks detector (GMR,TMR) binary memory stochastic device microwave oscillator Resistance Resistance Resistance Voltage Magnetic Field d.c. current Time Time spin wave emitter microwave detector … d.c. voltage Frequency Spin torque bricks: different functionalities at the nano-scale julie.grollier.free.fr ISAMMA 2013 12

Engineering new bricks julie.grollier.free.fr ISAMMA 2013 13

Engineering new bricks Can we tailor a spin torque memristor ? julie.grollier.free.fr ISAMMA 2013 13

Memristor Chua, IEEE Trans. Circuit Theory (1971) Memory - resistor v = M(q) i Strukov et al., Nature 2008 - Nano resistance - Non volatile - Tunable (multi-resistance states) - Non-linear ( V th ) R Digital multi-level OFF memory Plastic Synapse in ON Neuromorphic V architectures V th julie.grollier.free.fr ISAMMA 2013 14

Magnetic tunnel junction as a memristor Binary memory  2 state spin torque controlled memristor 400 350 How to obtain the quasi- Resistance (  ) 300 analog behaviour ? 250 200 150 -2 -1 0 1 2 d.c. current (mA) • other works : combine 2 state TMR + resistive switching Krzysteczko et al. APL 2009 - Prezioso et al. Adv Mater 2011 • purely electronic write operation  ST induced DW motion julie.grollier.free.fr ISAMMA 2013 15

Spin torque memristor : concept x     R R ( R R ) p AP P L R Resistance: proportion of D t parallel and anti-parallel t x 0 domains j  D  D  x J t q R   V R ( q ) i t D t x 0 x 1 - Resistance: DW position j - DW position: charge  injected R Memristor t x 2 x 1 Grollier et al. WO 2010/ 125181 A1 Wang et al. IEEE 2009 julie.grollier.free.fr ISAMMA 2013 16