1. Presentations Basics

2. Importance of presentations Real world -- Often more important than: –quality of work done –importance of discovery or invention Major factor in: –salary –promotions –opportunities

3. Elements of technical presentations Must include sales pitch –Why should audience listen –Preferably also in title Must start out with excitement –All technical details come later Should be brief –Real-world -- 20 minutes is very long time

4. Sales pitch Know your audience Example -- presentation to boss –find out background highest degree, major, thesis title? look up resume, publications, patents –find out goals examples: get rich quick, grow company Example -- presentation to customer –find out customer needs research details of customer business past and current problems anticipate future problems -- ex: competitors

5. Excitement Concentrate on important problem Example -- presentation to boss –sales trend over the past year Example -- presentation to customer –competitors latest advances

6. Technical details Describe new concepts by analogy –Example -- presentation to boss choose examples from boss’ field of expertise –Example -- presentation to customer choose examples from customers business

7. Detailed example Presentation of design and performance of laser intensity servo Audience: DVD manufacturer Sales pitch: –Want faster data rates? -- Use more stable laser. Excitement: –Ten-fold increase in data rate (projected) Technical details: –data rate limited by ability to recognize time-domain signal –laser intensity noise: »distorts signals, changes threshold levels, can give false signals –laser intensity servo reduces noise by factor of 10 or more »fixed data rate -- better bit error rate »fixed bit error rate -- faster data rate –project factor of 10 increase in data rate Choose title: Super-laser for ultra-fast DVD readout

8. Super-laser for ultra-fast DVD readout Stop! Don’t put that noisy laser in your quiet DVD reader Make your laser a “super-laser” Compatible with existing DVD designs Field installable upgrade

9. Problem (including background info) Fast DVD readout system –discriminate among code words in a set –faster than reading individual bits –not simple threshold -- correlation –intensity noise can distort Code word recognition ideal actual threshold Resolved bits ideal actualthreshold signal #1 intensity noise signal + noise Compare to signal #2 Effects of intensity noise signal #1 signal #2

10. Solution (note use of graphics) Add-on intensity servo Suppresses noise factor of 10 Ultra-high speed data Original noise prevents discrimination Reduced noise allows discrimination High speed data ideal actual Ultra high speed data ideal actual Original intensity noise Word #1 Word #2 Word #1 Word #2 Reduced intensity noise

11. Design details (example customer knows) Put AOM in laser path Undeflected beam: –no change in alignment –attenuated by increase in rf power Alternative: control current to laser diode –mode hops, frequency chirping ? rf reference detector Stable intensity Laser diode lens DVD readout detector Back-scatter deflected AOM

12. Conclusion (take-away message) Super-laser performance w/o super laser –Add-on intensity servo Order or magnitude increase in data rate Field upgradable Technical details –exist, but not exciting

13. Second example Type II quantum computers –illustrated importance of inventing names –audience will pay attention at least 3 min to find out what it means –enough time for motivation

14. Type II quantum computing Problem: –Moore’s law in trouble cannot continue to shrink existing technology –But need Moore’s law to maintain superiority commercial, military Solution: –See what a few atoms can do Scale up –Quantum computing Exponential speedup possible

15. Quantum computer types Type I = standard quantum computer –Shor’s, Grover’s, etc. Problem: –Must have 100’s of qubits to do anything real –After 10 years -- experiments lucky to get 2 scalable design –Will take too long to get to market Technology area will die Solution: –Type II quantum computer Large array of small quantum computers (nodes) Classical interconnects –Even 2 qubits per node can do interesting problems short-term product upgradable -- each qubit per node doubles comp. power directly scalable to Type I quantum computer N QUBITS/NODE M NODES CLASSICAL INTERCONNECTS TYPE II QUANTUM COMPUTER

16. Implementation Technical details –Use spins in solids Solid-state -- scalable Spins -- long lifetime –Problem with spins Isolated (long lifetime, difficult to excite) –Solution -- use optical Raman dark states Best of both worlds –strong optical dipole coupling –no effect on spin lifetime Specifics –Use array of nitrogen-vacancy complexes in diamond (NV diamond) LASER ILLUM. LENS PIXEL-REGISTERED PHOTON COUNTER ARRAY N-V ARRAY Type II Q.C. in NV diamond SAMPLE N-V DIAMOND ARRAY (J. MARTIN, ET.AL., APL 75, 1999)

17. Conclusion Type II Q.C. solves biggest problem w/ Q.C. –can get to market fast existing designs good enough to start –can upgrade on qubit at a time (per node) –can upgrade to Type I when technology ready Implement with NV diamond

18. Third example Ultra-slow and stopped light –illustrates importance of popular appeal –applications existed, but foreshadowed by sci-fi factor sounded like the impossible was now possible

19. Ultra-slow light Light speed: c = 186,000 mi/sec –strange things happen near v = c What if light moved at terrestrial speeds ? Light pulse slowed to speed of (racing) bicycle

20. Stopped light: Quantum storage Moore’s law applies to memory too –Memory will reach limit first: ~10YRS Sign that the end is near –Refrigerated hard drives Quantum computers need memory –Try running PC without RAM MOORE’S LAW FOR INTEGRATED CIRCUITS HARD DISK MEMORY BIT SPACING Physical spacing, nm 100 10 1 Year 92 94 96 98 2000 02 04

21. Slow light basics Group velocity is speed of information transfer –Can be different than phase velocity Example: near steep refractive index dispersion –transparency has correct sign PROBE DETUNING (arb. units) 0 0.5 1 ABSORPTION -0.5 0 0.5 REAL PART of 

22. Ultra-slow light in a solid SIMPLIFIED LEVEL DIAGRAM 17.3 MHz 10.2 4.6 4.8 ±1/2 ±3/2 ±5/2 ±3/2 ±5/2 3H43H4 1D21D2 COUPLING PROBE REPUMP 100% 0% PROBE TRANS. PROBE DETUNING (MHz) -21 2 0 TRANSPARENCY Pr: Y 2 SiO 5 0100 200  sec Transmitted Probe (%) 0 12 Slowed light Incomplete absorption of probe Input probe beam (x0.25) SLOW LIGHT DEMO Delay = 100  sec = 33 m/s (70 mph)

23. Stopped light in a solid Solid state material better for storage applications Technical details: –Control laser intensity determines light speed –Zero intensity stops the light pulse –Restore control laser to recover stopped light Transmission (%) Delay Time (  sec) 300 0100200 400 0 12 6 Control laser Slow light Stopped light

24. Conclusion Ultra slow and stopped light –Works in a solid too Excellent potential for quantum storage