QUANTUM LEAP

INSIDE THE TANGLED QUEST FOR THE FUTURE OF COMPUTING

TIME magazineFebruary 17, 2014

04/11/2023 jgillis767@aol.com 2

Two of the great scientific undertakings of the 20th century – quantum physics

and digital computing

“What would happen if we built a computer that operated under quantum rules instead of classical ones? Could it be done? And if so, how? And more important, would therebe any point .”

Richard Feynman (in the 1980’s)

The Merging

04/11/2023 jgillis767@aol.com 3

Quantum Computers

• Classical computers work with information in bits. Each bit can be either a 1 or a 0 at any one time. This is the foundation of digital computing as we know it, and it operates only in linear fashion.

• Quantum computers operate with bits that can be 1, or 0, or 1 and 0 at the same time.

04/11/2023 jgillis767@aol.com 4

Qubits

• In a superposed state, a quantum bit exists as two equally probable possibilities.

• If a single quantum bit (or qubit) can be in two states at the same time, it can perform two calculations at the same time.

• Two qubits could perform four simultaneous calculations; three could perform eight, and so on. The power grows exponentially.

04/11/2023 jgillis767@aol.com 5

111 000011 101110 001010 100

101CLASSICAL

QUANTUM

FASTER CALCULATIONSBecause its datacan exist in multiple states, a quantum computer canperform multipleoperations simultaneouslyinstead of one by one.

Simultaneous Operations

04/11/2023 jgillis767@aol.com 6

D-Wave Two

• The supercooled niobium chip at the heart of the D-Wave Two has 512 qubits and therefore could in theory perform 2512 operations simultaneously.

• That’s more calculations than there are atoms in the universe, by many orders of magnitude.

• “This is not just a quantitative change.”

Colin Williams* – D-Wave

* Former Stephen Hawking research assistant at Cambridge

04/11/2023 jgillis767@aol.com 7

Software

• An adiabatic quantum computer is a totally new proposition for software development.

• “It’s not about writing recipes or procedures. It’s more about kind of describing ‘What does it mean to be an answer? And doing that in the right way and letting the hardware figure it out.”

William Macready, D-Wave’sVP of Software Engineering

04/11/2023 jgillis767@aol.com 8

A Long Shot?

• NSA has an $80 million quantum-computing project. (According to an Edward Snowden leaked document)

• In-Q-Tel is in. (High tech investment arm of the CIA)

• Lockheed Martin (Defense contractor)

• Draper Fisher Jurvetson (Venture capital, Skype, Tesla Motors)

• Jeff Bezos (Amazon)

• NASA computing lab (Largely funded by Google)

04/11/2023 jgillis767@aol.com 9

The Unconvinced

• Outright debunkings have been lobbed from ivory towers. “They are not qubits, they are just plain old bits.”

• “…quantum effects…means we are able to store superpositions in such a way that the system retains its ‘fuzziness’ or quantum coherence, so that it can perform tasks that are impossible otherwise. There is no evidence that the D-Wave is using quantum effects.”

Christopher Monroe – Joint Quantum Institute – University of Maryland

04/11/2023 jgillis767@aol.com 10

“It’s fine,” he says (about the skeptics). “It’s good.Science progresses by rocking the ship. Things likethis are a necessary component of forward progress.”

Geordie Rose, D-Wave’s co-founder and chief technology officer

04/11/2023 jgillis767@aol.com 11

Definitions

• Superposition: A quantum system can be in more than one state at the same time, and even more than one place at the same time.

• Uncertainty: The more precisely we know the position of a particle, the less precisely we know how fast it is travelling – we cannot know both at the same time.

04/11/2023 jgillis767@aol.com 12

Definitions

• Adiabatic Process: A process that occurs without the transfer of heat or matter between a system and its surroundings

• Quantum Entanglement: when pairs or groups of particles are generated or interact in ways such that the quantum state of each particle cannot be described independently. A quantum state.

04/11/2023 jgillis767@aol.com 13

Definitions

• Simulated annealing: a process for a good approximation of the global optimum of a given function in a large search space. May be more efficient than exhaustive enumeration.

• Quantum annealing: Starts from a quantum-mechanical superposition of all possible states with equal weights. It may outperform simulated annealing under certain conditions.

04/11/2023 jgillis767@aol.com 14

04/11/2023 jgillis767@aol.com 15

Veritas?

jgillis767@aol.com