The Second Quantum Revolution
Analog then, Digital now, Quantum next
Quantum physics was established in the early 1900s by a group of physicists in an attempt to describe the newly discovered phenomena of the microscopic world. In the past hundred years, we have witnessed "the first quantum revolution" where quantum properties are partially used to develop world-changing technologies. These include transistors which led to the digital age, lasers, LED, solar cells, MRI and many more. But this is only the beginning.
We are now entering into "the second quantum revolution" where individual atoms / photons are manipulated to bring out the full potential of quantum mechanics. Applications include quantum computing, quantum simulation, quantum cryptography and quantum sensors. These developments bring the new era of information processing technologies.
In the past 30 years, quantum technologies have made tremendous progress from Nobel-wining experiments to a large investment from corporates and governments worldwide. Examples include a 2 billion-euro European Quantum Flagship that took place in 2018, a 1.2 billion-USD Quantum Computing Bill from US in 2018 and a 10 billion-USD National Quantum Centre in China. Investments from private companies include Google, IBM, Intel, Amazon, Microsoft, Alibaba, Lockheed Martin, Airbus and many more.
In 2019, Google has demonstrated "quantum supremacy" where a quantum computer computes in seconds a specific task that requires several days of the best supercomputer . In 2020, China has demonstrated similar achievement, computing tasks that require 2.5 billion years of a conventional computer . Nevertheless, these quantum devices are still very noisy and cannot be used for real-word applications. The European Commission has set out the goal to built a full-fledged quantum computer by 2035. If successful, such machines would have a capability to disrupt the standard crytosystems currently employed in all digital platforms.
 F. Arute et. al., Nature, 574, 505–510 (2019)
 H.S. Zhong et. al., Science, 0036-8075 (2020)
What exactly does it mean by quantum?
A quantum (plural: quanta) is the minimum amount of any physical entity involved in a physical process. The word is used to describe a smallest and undivided unit of the magnitude of a physical property. An example is the energy of light which can take on only discrete values and can be only equal to integer multiples of one quantum (photon). This is considered as one of the weird properties of nature, of which the 400-year-old classical treatment of nature cannot explain.
What does it mean for businesses?
Quantum is a new era after Analog and Digital. Similar to the change from Analog to Digital, Quantum opens up new business landscapes which requires an entirely new way of thinking. Conventional programmers and computer scientists cannot directly translate their expertise into quantum technology without a major re-skilling. As recommended by several leading consulting firms such as McKinsey, BCG, Accenture and Gartner, businesses should take actions now to prepare themselves for the quantum era.