Devices exploiting superposition and entanglement can vastly increase performance or accomplish what was once thought to be impossible

New quantum technology will enable the following:

  • A bathing cap that can watch individual neurons, allowing others to monitor the wearer’s mind.
  • A sensor that can spot hidden nuclear submarines.
  • A computer that can discover new drugs, revolutionise securities trading and design new materials.
  • A global network of communication links whose security is underwritten by unbreakable physical laws.

Exploiting superposition and entanglement enables devices that vastly outperform existing ones—and accomplish things once thought to be impossible.

Improving atomic clocks by incorporating entanglement, for example, makes them more accurate than those used today in satellite positioning. That could improve navigational precision by orders of magnitude, which would make self-driving cars safer and more reliable. And because the strength of the local gravitational field affects the flow of time (according to general relativity, another immensely successful but counter-intuitive theory), such clocks would also be able to measure tiny variations in gravity. That could be used to spot underground pipes without having to dig up the road, or track submarines far below the waves.

Rather than scale devices down, quantum technologies employ the unusual behaviors of single atoms and particles and scale them up.

After decades of work in the laboratory, a raft of different devices and approaches relying on quantum-mechanical effects are now nearing market-readiness. It has taken so long mainly because the components that make them up had to be developed first: ever-better lasers, semiconductors, control electronics and techniques to achieve the low temperatures at which many quantum systems perform best.

RSK, an environmental consultancy involved in cleaning up brownfield sites and the like, reckons that a third of construction projects overrun by up to a month, and another third by two months or more, and that half of these delays arise because of underground surprises. The company is collaborating with the University of Birmingham in Britain on fieldworthy quantum gravity sensors, in the hope of deploying them in big infrastructure projects. Other efforts to develop cheap sensors have drawn interest from companies such as Schlumberger, an oilfield-services giant, and Bridgeporth, a surveying firm.

Military types are interested, too. “You can’t shield gravity,” says David Delpy, who leads the Defence Scientific Advisory Council in Britain’s defence ministry. Improved gravity sensors would be able to spot moving masses under water, such as submarines or torpedoes, which could wipe out the deterrent effect of French and British nuclear submarines. Quantum gravimeters could precisely map geological features from the gravitational force they induce. That would help with getting around in places where satellite-navigation signals are not available—“a kind of Google Maps for gravitation”, as Dr Delpy puts it.
And gravity, the theory of relativity also says, is just one manifestation of acceleration: a good gravimeter is a good accelerometer. And a good accelerometer is a good vibration sensor. Once they are small enough and good enough, all these high-precision devices will be of great interest to carmakers, and in particular to the autonomous-vehicle industry, the success of which will depend on accurate sensing of the movements of cars and their surroundings. Bosch, a German firm that is the world’s largest maker of automotive components and a supplier to many other industries, already has its eye on quantum-technological enhancements to its products.

Other aspects of quantum theory permit messaging without worries about eavesdroppers. Signals encoded using either superposed or entangled particles cannot be intercepted, duplicated and passed on. That has obvious appeal to companies and governments the world over. China has already launched a satellite that can receive and reroute such signals; a global, unhackable network could eventually follow.

The advantageous interplay between odd quantum effects reaches its zenith in quantum computers. Rather than the 0s and 1s of standard computing, a quantum computer’s bits are in superpositions of both, and each “qubit” is entangled with every other. Using algorithms that recast problems in quantum-amenable forms, such computers will be able to chomp their way through calculations that would take today’s best supercomputers millennia. Even as high-security quantum networks are being developed, a countervailing worry is that quantum computers will eventually render obsolete today’s cryptographic techniques, which are based on hard mathematical problems.

SOURCEs- Economist, McKinsey

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