Friday, March 9, 2018

"Google Chases Quantum Supremacy with 72 Qubit Processor"

This may be important. For quite a few years the point at which quantum computers would surpass conventional was assumed to be 54 qubits.
Then late last year it became apparent that conventional computers were still superior to quantum 'puters in most respects at the 54 qubit level. More after the jump.

From the high performance computing gurus at HPCwire:
March 7, 2018
Google pulled ahead of the pack this week in the race toward “quantum supremacy,” with the introduction of a new 72-qubit quantum processor called Bristlecone. The gate-based superconducting system will be instrumental in Google’s efforts to demonstrate the first quantum technology to show advantage over today’s leading classical machines.

Bristlecone (so nicknamed due to the qubits being arranged in a pinecone pattern) will be employed as a testbed for researching system error rates and boosting scalability of Google’s qubit technology and for exploring near-term applications in quantum simulation, optimization, and machine learning.
The Mountain View, Calif.-based research team created Bristlecone by scaling up its previous 9-qubit array. Announced by the Google team last year, that (smaller) system “demonstrated low error rates for readout (1%), single-qubit gates (0.1%) and most importantly two-qubit gates (0.6%),” according to Julian Kelly, Research Scientist, Quantum AI Lab, who shared details of the new processor in a blog post.
Bristlecone is Google’s newest quantum processor (left). On the right is a cartoon of the device: each “X” represents a qubit, with nearest neighbor connectivity. Source: Google
Bristlecone is Google’s newest quantum processor (left). On the right is a cartoon of the device: each “X” represents a qubit, with nearest neighbor connectivity. Source: Google “This device uses the same scheme for coupling, control, and readout, but is scaled to a square array of 72 qubits,” stated Kelly. “We chose a device of this size to be able to demonstrate quantum supremacy in the future, investigate first and second order error-correction using the surface code, and to facilitate quantum algorithm development on actual hardware.”

Google’s goal is to achieve similar performance to the best error rates of the 9-qubit device, but do so across all 72 qubits of Bristlecone. It’s essentially a recipe for achieving quantum supremacy, which according to the Google team’s calculations “can be comfortably demonstrated with 49 qubits, a circuit depth exceeding 40, and a two-qubit error below 0.5%.”

Circuit depth refers to how many logical operations a quantum processor can carry out before coherence decays....MORE
Quite a flurry of activity the last few months:
March 2017
"Google's Quantum AI Laboratory set out investment opportunities on the road to the ultimate quantum machines" (GOOG).

July 2017
Computing: Will Quantum Devices Outperform Classical Computers by Year-end 2017? (thus achieving 'quantum supremecy')

July 2017
Yeah, I Got Your Bitcoin Right Here: "‘Quantum Checks’ to Replace Cryptocurrencies in the Future?"
One of Mr. Keohane's Further Reading links is to a Bloomberg article that asks in its headline "Why Can’t Americans Ditch Checks?".

Why? I'll tell you why. If the rest of the world wants to go with Venmo or cryptocrap that's just fine.

We're roughly nine months from real—honest-to-goodness—quantum supremecy, the moment when quantum computers show they actually are superior to classical 'puters.

And with three of the top five quantum co's. in the U.S. it's a pretty good bet that it will be American thieves emptying those supposedly hack-proof wallets around the world and the American companies will be using the Indian guy's idea (below) to move beyond old-fashioned crypto.

And Deluxe Corp. (and maybe De La Rue too) will be going all Schrödinger on the fanboys and the kids will be saying "Ehereum? That's sooo 2017."

Or not.
Predicting is hard.  
Nov. 2017
Questions America Wants Answered: "Is Quantum Computing an Existential Threat to Blockchain Technology?"

January 2018
One More Reason Cryptography May Not Stand Up to Quantum Computers

February 2018
Supremecy—Quantum Algorithms Struggle Against Old Foe: Clever Computers