Saturday, 21 April, 2018

Google Chip Takes Aim At 'Quantum Supremacy'

Google Chip Takes Aim At 'Quantum Supremacy' Google Chip Takes Aim At 'Quantum Supremacy'
Sherri Watson | 06 March, 2018, 21:08

The company with the friendly-sounding name has previewed "Bristlecone", its experimental quantum computing processor it wants to use to solve real-world problems, and be first to achieve something called "quantum supremacy".

Google's Quantum A.I. Labs demonstrated the Bristlecone chip in Los Angeles on Sunday at the annual meeting of the American Physical Society. Eager to prove that "quantum supremacy" is possible, Google is now experimenting with a 72-qubit chip codenamed Bristlecone that also yields low error rates. It was created to preserve the underlying physics of Google's previous 9-qubit linear array technology with low error rates for readout (1 per cent), single-qubit gates (0.1 per cent) and two-qubit gates (0.6 per cent).

The 72-qubit design, dubbed "Bristlecone", aims to "preserve the underlying physics" of its predecessor, scaling up "the same scheme for coupling, control, and readout".

Quantum hardware, which uses multi-state "qubits" instead of today's on-off binary bits, are fast making the leap from theoretical to actual.

One of the primary encumbrances to building a quantum computer is the comparatively high error rate that quantum processors are prone to. With Google, Intel, various academics, Microsoft, and IBM - among many others - all vying for that breakthrough moment, the race to quantum supremacy is only just beginning. We can assign a single system error by applying random quantum circuits to the device and checking the sampled output distribution against a classical simulation.

Google claimed that quantum processors with even low-power qualities can outperform the most powerful supercomputers for particular applications, paving the way for scientific research.

Bristlecone will serve as a testing ground for the scalability of Google's qubit technology, improvements on system error rates and ML, simulation and optimization applications. "Operating a device such as Bristlecone at low system error requires harmony between a full stack of technology ranging from software and control electronics to the processor itself", says the Google Research Blog. "Getting this right requires careful systems engineering over several iterations", said Google.

Of note, the achievement of quantum supremacy would be one step closer to breaking public-key cryptography, as schemes such as RSA are built around the notion that factoring large numbers is practically too hard.

Other organizations are also researching quantum computing techniques.

Intel's 48-qubit test chip.