Schroedinger's killer app. Race to build the world's first quantum computer

444 Pages·2013·4.18 MB·English

by  Dowling

SCIENCE/PHYSICS Schrödinger’s Killer App
Schrödinger’s Killer App Race to Build the World’s First Quantum Computer
Race to Build the World’s First Quantum Computer
Written by a renowned quantum physicist closely involved in the U.S. government’s
Schrödinger’s Killer App: Race to
development of quantum information science,
Build the World’s First Quantum Computer
presents an inside look at the government’s
quest to build a quantum computer capable of solving complex mathematical problems
and hacking the public-key encryption codes used to secure the Internet. The “killer
app” refers to Shor’s quantum factoring algorithm, which would unveil the encrypted
communications of the entire Internet if a quantum computer could be built to run the
algorithm. Schrödinger’s notion of quantum entanglement—and his infamous cat—is at
the heart of it all.
The book develops the concept of entanglement in the historical context of Einstein’s
30-year battle with the physics community over the true meaning of quantum theory.
It discusses the remedy to the threat posed by the quantum code breaker: quantum
cryptography, which is unbreakable even by the quantum computer. The author also covers
applications to other important areas, such as quantum physics simulators, synchronized
clocks, quantum search engines, quantum sensors, and imaging devices. In addition, he
takes readers on a philosophical journey that considers the future ramifications of
quantum technologies.
Interspersed with amusing and personal anecdotes, this book presents quantum computing
and the closely connected foundations of quantum mechanics in an engaging manner
accessible to non-specialists. Requiring no formal training in physics or advanced
mathematics, it explains difficult topics, including quantum entanglement, Schrödinger’s
cat, Bell’s inequality, and quantum computational complexity, using simple analogies.
K14277
ISBN: 978-1-4398-9673-0 Jonathan P. Dowling
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9 781439 896730
K14277_Cover_mech.indd 1 3/19/13 11:09 AM
Schrödinger’s Killer App
Race to Build the World’s First Quantum Computer

Schrödinger’s Killer App
Race to Build the World’s First Quantum Computer
Jonathan P. Dowling
Boca Raton London New York
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Version Date: 20130226
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Dedicated to My Parents
Patricia Mary Dowling
and
John Philip Dowling

Contents
Preface ix
1 The Early Years—When Einstein Attacks! 1
Certain Uncertainties 5
All I’m Ever Going to Be Is Incomplete 7
Fairies, Gremlins, and Magic Dice 19
The Inverted Earth Society 28
The Cat in the App 35
2 For Whom the Bell Tolls 49
Clanking Contraptions and Cantankerous Codgers 55
Freedom of Choice, French Finesse, and Loopholes 63
I Never Metaphysics I Didn’t Like 71
3 The Quantum Codebreaker 77
The Trouble with Thulium 82
Turing Machines and a Deutsch Treat 91
Your Pad or Mine? 106
The People’s Key 113
The Bolt from the Blue 120
4 You’re in the Army Now 131
The Great Quantum Diaspora 132
The Notebook, The Spy, and The Workshop 134
The Unlying Lands 171
Interior Panel Siding 178
Needle in a Haystack 179
Quantum Computing in a Coffee Cup—When the Buzz Wears Off 192
D-Wave, BOSS, D-Wave 207
5 More Gadgets from the Quantum Spookhouse 227
Blessed Are the Codemakers 227
Quantum Repeaters and Earth-to-Space Quantum Cryptography 245
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viii Contents
Beam Me Up, Charlie 256
The Tale of the True Timepiece 274
From Quantum Computers to Quantum Sensors 283
Light Blips Shrink Chips 299
The Great Clock Synchronization Saga 308
6 Hilbert Space—The Final Frontier 327
Quantum Technology in a FLASH 327
Qubits, Four Bits, Six Bits, a Dollar 355
The Church of the Larger Hilbert Space 378
To Go Where No Mad Scientist Has Gone Before 396
PREFACE
Since 1994, I have been closely involved in the development of quantum infor-
mation science in the United States. I was co-organizer of the first Department
of Defense (DoD) workshop on the topic (held in Tucson in 1995), and from
1994 through 1998, I served as a DoD reviewer of the program. From 1998
through 2004, I continued in this role as a scientist at the NASA Jet Propulsion
Laboratory. From 2004 to the present, I have served as a scientific academic
reviewer of quantum technologies for the government in my current post at
Louisiana State University. (Geaux Tigers!) This book consists of my personal
history of the development of the field of quantum computing in the United
States, constructed primarily from memory and detailed notes, from my point
of view as a quantum physicist and a member of the DoD advisory programs.
The “killer app” (or “killer application”) in the title refers to Shor’s quantum
factoring algorithm, which—if only a quantum computer could be built to run
it—would unveil the encrypted communications of the entire Internet for all to
see. (Your credit card number would never be safe again.) I call this algorithm
Schrödinger’s Killer App, instead of Shor’s Killer App, because Schrödinger’s
notion of quantum entanglement is at the heart of it all (and as an alliterative
allusion to Schrödinger’s infamous half-alive and half-dead cat).
From international multi-billion-dollar financial transactions to top-secret
government communications, all would be vulnerable to such a quantum code
breaker. Thus, the race is on to be the first to construct one, as the winner will
hold the key to the entire Internet. My particular history leads me to focus on
the US government’s role in all this, specifically the DoD and other intelligence
agencies that are vitally interested in the secret-code-breaking ability of the
quantum computer.
To keep myself out of hot water (and keep my friends and colleagues at such
agencies from despair), when referring to real persons in this book, particu-
larly those in the intelligence agencies, I resort to a first-name-only reference
(or first name with last initial in case of confusion). I take full responsibility for
any errors in fact or fiction contained herein. (I am Irish, and under Irish rules,
the truth or falsehood of a story always plays second fiddle to the entertain-
ment value that it has and the moral that it provides. And yes—I have kissed
the Blarney stone.)
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