1. Micky Holcomb West Virginia University Bristow, Lederman, Stanescu & Wilson Micky Holcomb West Virginia University Bristow, Lederman, Stanescu & Wilson mikel.holcomb@mail.wvu.edu Overcoming Roadblocks in Future Computing at the Center for Energy Efficient Electronics at Marshall and WVU http://ceee.eberly.wvu.edu/

2. Progress Through Size 1950s

3. Shortening the Race = Faster

4. ~ Every 2 years, Twice as many transistors can fit in the same space With the same cost! Doubling (Moore’s Law) 2 12 years later Today, >200 million transistors can fit on the head of a pin! By 2050 - if trends continue - a device the size of a micro-SD card will have storage of ~ 3x the brain capacity of the entire human race!

5. Silicon In a transistor, a voltage on the metal can induce flow of electricity between the two other contacts called the source (In) and drain (Out). The flow of electricity is affected by: properties of the insulator, the area of A&B and the insulator thickness 1) Making Them Smaller A B In Out Voltage (C) Insulator Metal

6. Quantum Tunneling?!? Electrons are lazy! If the hill isn’t too wide, they tunnel through it. Not good.

7. Insulating properties (resists electron flow) “Plays nice” with current Si technology (temperature and quality) Many materials have been tried but none are as cheap and easy to manipulate as existing SiO 2. 2) Replacement Oxides

8. 3) Strain Industry found that it could improve electron travel by straining—essentially squeezing—silicon. Strain can allow quicker, more efficient transfer of electrons. Stress-Apparatus Wilson (Marshall)

9. Reaching the Limits We are reaching the limit that these strategies can continue to improve technology. 1) Scaling 2) Replacements 3) Strain

10.  4) Different Approach: Magnetism

11. 0 0 1 Problems with Magnetic Fields Require a lot of power Heating problems Difficult to localize – limits size Magnetic field Using Magnetism

12.  Electrical Control of Magnetism - Simple idea: Grow a magnetic material on top of an electric material Materials with strong coupling between electricity and magnetism at room temperature are rare - Problem: the physics at boundaries is not yet well understood

13. LSMO PZT Mn 2.5+ LSMO thickness (nm) Mn valency Mn 3.3+ Zhou, Holcomb, et. al. APL, submitted One monolayer ~ Mn 2.5+ (based on data) Magnetoelectric Interfaces Holcomb Group La 0.7 Sr 0.3 MnO 3 We can control magnetization in LSMO through thickness engineering. LSMO PZTSTO La 0.7 Sr 0.3 MnO 3 PZT SrTiO 3 Aberration-Corrected STEM (Collaboration with James LeBeau, NCSU) Combined Individual Elements Smooth Interfaces

14. Thin Topological Insulators Glinka, Bristow, Holcomb, Lederman, APL, 2013. Simplified Setup

15. Electric Magnetic Magnetoelectric and two dimensional offer a promising pathway to new devices. As computers continue to get smaller, the physics becomes more interesting. These materials can be imaged and studied at WVU, Marshall and national laboratories. Exciting information about the structure and interface has provided a deeper understanding which we hope to exploit for improved technology. Summary This work is funded by