Imagine you only have five minutes to find an “X” written on a page of a book in the Library of Congress (which has 50 million books). It would be impossible. But if you were in 50 million parallel realities, and in each reality you could look through the pages of a different book, in one of those realities you would find the “X.”
– Eric Ladizinsky
Co-founder of the quantum computing company D-Wave
In other words, a regular computer is ‘you’ running around like a crazy person trying to look through as many books as possible in five minutes. A Quantum computer is you split into 50 million ‘yous’, casually flipping through one book in each reality.
To speed computation, quantum computers tap directly into an unimaginably vast fabric of reality—the strange and counter-intuitive world of quantum mechanics. They make direct use of quantum-mechanical phenomena, such as superposition and entanglement, to perform operations on data. The same way traditional computers work with streams of binary bits, a quantum computer maintains a sequence of qubits. A single qubit can represent a one, a zero, or any quantum superposition of those two-qubit states; a pair of qubits can be in any quantum superposition of 4 states, and three qubits in any superposition of 8 states.
QUBITS – SUPERPOSITION & ENTANGLEMENT
Think of a qubit as a coin. A coin has two distinct faces, heads and tails. Consider tossing a coin in the air. What face does it represent now? Is it heads or tails? In a weird sense, it is a combination of both and until it collapses we have no way of knowing which one it is. A qubit in a similar fashion is the superposition of two states 0 and 1, also being considered as the non-binary state.
The qubits present in quantum computers consist of two atoms and are magnetically suspended in extreme cold, just fractions of a degree above absolute zero. Researchers are also experimenting with superconducting materials, ions held in ion traps or individual neutral atoms, as well as molecules of varying complexity to build them.
Four classical bits can be in 24 different configurations at a time. That’s 16 possible combinations out of which you can use just one. Four qubits in superposition, however, can be in all of those 16 combinations at once. This number grows exponentially with each extra qubit. Therefore, twenty such qubits can store a million values in parallel. Another weird and unintuitive property qubits can have is entanglement – a close connection that makes each of the qubits react to a change in the other state instantaneously no matter how far apart they are. This means that when measuring just one entangled qubit you can directly deduce properties of its partners without having to look for that qubit.
Such computational capabilities are highly powerful, and the term “quantum supremacy” was introduced by Caltech’s John Preskill to mark the moment quantum computers will exceed the processing power of conventional silicon.
AREAS REVOLUTIONIZED BY QUANTUM COMPUTING
Online Security
There will be good and bad news for online security once there is widespread adoption of quantum computers. The bad? Our current data encryption tactics will become obsolete and can be easily hacked by the Shor’s algorithm, an algorithm that quantum computers use to unravel our online data encryption. The good news is that significant work has been done to develop quantum encryption methods such as quantum key distribution, an ultra-secure communication method that requires a key to decipher a message.
Artificial Intelligence
The information processing that is critical to improving machine learning is ideally suited to quantum computing. Quantum computers can analyze large quantities of data to provide artificially intelligent machines with the feedback required to improve performance.
Drug Development
Since quantum computers can review multiple molecules, proteins and chemicals simultaneously, they make it possible for chemists to determine viable drug options quicker.
Traffic control
Quantum computers will be able to quickly calculate the optimal routes concurrently, which would allow for efficient scheduling and would reduce traffic congestion. For similar reasons, quantum computers are also powerful for optimizing supply chains, air traffic control, fleet operations and deliveries.
Improved weather forecasting and climate change predictions
Since quantum computers can analyze all the data at once, meteorologists will have a much better idea of when bad weather will strike to alert people to ultimately save lives, anguish and money.
While D-Wave announced the D-Wave 2000Q Quantum Computer and First System Order in January early this year, Google announced its plan of running a 50-qubit computer by the end of 2017, and IBM has plans to hit that mark soon too. IBM’s latest machine, a superconducting model weighing in at 17 qubits, is still in the lab, but a five-qubit machine is running and available to the public, with a 16-qubit computer in beta testing.