Nanocomputing by field coupled nanomagnets
Download
1 / 33

NANOCOMPUTING BY FIELD-COUPLED NANOMAGNETS - PowerPoint PPT Presentation


  • 107 Views
  • Uploaded on

NANOCOMPUTING BY FIELD-COUPLED NANOMAGNETS. AUTHORS : Gyorgy Csaba Alexandra Imre Gary H. Bernstein Wolfang Porod (fellow IEEE) Vitali Metlushko REFERENCE : IEEE TRANSACTION ON NANOTECHNOLOGY, VOL 1, NO. 4, DECEMBER 2002. REPORT EDITED BY : Andrea Anzalone Marco Scagno CIRCLE :

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' NANOCOMPUTING BY FIELD-COUPLED NANOMAGNETS' - zudora


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Nanocomputing by field coupled nanomagnets
NANOCOMPUTING BY FIELD-COUPLED NANOMAGNETS

  • AUTHORS:

    Gyorgy Csaba

    Alexandra Imre

    Gary H. Bernstein

    Wolfang Porod (fellow IEEE)

    Vitali Metlushko

  • REFERENCE :

    IEEE TRANSACTION ON NANOTECHNOLOGY, VOL 1, NO. 4, DECEMBER 2002


  • REPORT EDITED BY :

    Andrea Anzalone

    Marco Scagno

  • CIRCLE :

    course of:

    NANOELETTRONICA 1

    professor:

    E. DIZITTI


Summary
SUMMARY

  • INTRODUCTION

  • SPICE MODEL FOR SIMULATION

  • NANOMAGNETIC WIRE

  • MAGNETIC MAJORITY GATE

  • FINAL REMARKS


Introduction
INTRODUCTION

Achievements:

from

thin magnetic film technologies

to

patterned magnetic media on the deep

submicron and nanoscale


INTRODUCTION

Basic structure:

use of individual ferromagnetic dots

ONE DOT ONE BIT OF INFORMATION


INTRODUCTION

ADVANTAGES:

  • Lower energy dissipation

  • Higher speed

  • Larger storage density


INTRODUCTION

TARGET DEVICES :

STORAGE :

Hard Disk Drives (HDDs)

Magnetic Random Access Memories (MRAM)

NANOMAGNETIC WIRES

MAGNETIC MAJORITY GATES

( “programmable” elementary logic devices )



SPICE MODEL FOR SIMULATION device (b) Field-coupled structure

Presence of dipolar interaction between neighbouring magnetic particles:

THIS EFFECT IS :

a disadvantage for HDDs and MRAM

( limit to packing density of dots)

an advantage for nanomagnetic wires and magnetic majority gates


SPICE MODEL FOR SIMULATION device (b) Field-coupled structure

We need models for:

  • each single micromagnetic dot

  • interaction dot to dot


SPICE MODEL FOR SIMULATION device (b) Field-coupled structure

1) General mathematical approach :

use of the well-established theory of micromagnetics

  • PROBLEM : this theory is:

    • TOO COMPLEX

    • COMPUTATIONALLY INTENSIVE


SPICE MODEL FOR SIMULATION device (b) Field-coupled structure

2) Use of SPICE macromodels :

based on single-domain approximation ( SDA )

THIS IS A NEW, INNOVATIVE

SOLUTION

useful to design large dots arrays


SPICE MODEL FOR SIMULATION device (b) Field-coupled structure

ADVANTAGES:

  • more efficient simulations

  • very powerful possibility to design nanomagnetic structures integrated in microelectronic circuits


FIG 2 - Circuit blocks of two coupled nanomagnets device (b) Field-coupled structure i e j



NANOMAGNETIC WIRE inputs and three-outputs

WHAT IS IT ?

  • It is a line of coupled nanomagnets


FIG 4 - Operating scheme of the nanowire. (a) Initial configuration (b) High-field state before and (c) after the application of the input. (d) Final ordered state.


NANOMAGNETIC WIRE configuration (b) High-field state before and (c) after the application of the input. (d) Final ordered state.

Digital information is represented by the vertical component of the magnetization (mz)

  • mz = 1 if BIT = ‘1’

  • mz = -1 if BIT = ‘0’


NANOMAGNETIC WIRE configuration (b) High-field state before and (c) after the application of the input. (d) Final ordered state.

An external magnetic field is applied to drive the dots from an arbitrary initial state to the ordered final state


NANOMAGNETIC WIRE configuration (b) High-field state before and (c) after the application of the input. (d) Final ordered state.

STANDARD STEPS FOR A NANOWIRE :

  • 1) we considered a general initial configuration


NANOMAGNETIC WIRE configuration (b) High-field state before and (c) after the application of the input. (d) Final ordered state.

STANDARD STEPS FOR A NANOWIRE :

  • 2) an initial strong external field erase the “memory” of the initial state:

  • mz = 0 for each dot


NANOMAGNETIC WIRE configuration (b) High-field state before and (c) after the application of the input. (d) Final ordered state.

STANDARD STEPS FOR A NANOWIRE :

  • 3) an input current influence the magnetization of the input dot


NANOMAGNETIC WIRE configuration (b) High-field state before and (c) after the application of the input. (d) Final ordered state.

STANDARD STEPS FOR A NANOWIRE :

  • 4) the external field is adiabatically lowered and the input signal can propagate through the structure


FIG 5 - SPICE simulation of the nanowire. The driver current and the mz components are shown . The phases (a), (b), (c), (d), corresponds to schematics of FIG 4 . The dashed line is the pump field


MAGNETIC MAJORITY GATE and the

IT IS THE BASIC LOGIC BUILDING BLOCK OF NANOMAGNETIC CIRCUITS


FIG 6 - Physical layout of the majority gate. The input dots (dot 2, 3, 4) are driven by electric wires and the result of the computation is represented by dot 6


MAGNETIC MAJORITY GATE (dot 2, 3, 4) are driven by electric wires and the result of the computation is represented by dot 6

IT HAS:

  • 3 inputs

  • 1 output

  • The device is clocked by an external pumping field in a similar way to the nanowires


MAGNETIC MAJORITY GATE (dot 2, 3, 4) are driven by electric wires and the result of the computation is represented by dot 6

THE INPUTS HAVE NO PREDEFINED FUCTIONS:

if we force one of them to ‘1’ the device realizes a logic NOR function between the other two inputs and the output

if one input is ‘0’ the gate computes the NANDfunction


FIG 7 - SPICE simulation of the magnetic majority gate. The currents correspond to the perpendicular magnetization of the dots. The dashed line is the pump field.


FINAL REMARKS currents correspond to the perpendicular magnetization of the dots. The dashed line is the pump field.

Need of input wires and output sensors only at the interface of the device:

WHITIN IT EACH SINGLE BASIC MODULE CAN BE CONNECTED USING NANOWIRES

  • High integration density:

  • above TERABIT / inch²


FINAL REMARKS currents correspond to the perpendicular magnetization of the dots. The dashed line is the pump field.

If only quasi-static behaviour is of interest the dinamic circuit model can be replaced by its non-linear static model:

IT DEPENDS ON GEOMETRIC PARAMETERS :

High pliability for the models

  • USE OF NANOMAGNETICS ARRAYS TO SIMULATE BEHAVIOUR OF GENERAL NON LINEAR CIRCUITS


FINAL REMARKS currents correspond to the perpendicular magnetization of the dots. The dashed line is the pump field.

We have seen that a magnetic majority gates can perform basic logic functions ( NAND & NOR ):

we can suppose to use more gates (connected with nanowires) to realize any kind of boolean function and more in general to manage signal-processing tasks


FINAL REMARKS currents correspond to the perpendicular magnetization of the dots. The dashed line is the pump field.

PROMISING APPLICATIONS FOR THE FUTURE:

  • Intelligent magnetic field sensors

  • Processing-in-memory type architectures

  • Complex signal-processing units


ad