Personal tools

Quantum Computing

Rose Garden_Hyde Park_London_UK_060815B
(Rose Garden, Hyde Park, London, UK - Hsi-Pin Ma)

 

 

What is a Quantum Computer?


[BBC]: "A quantum computer is a machine that is able to crack very tough computation problems with incredible speed - beyond that of today's "classical" computers.

In conventional computers, the unit of information is called a "bit" and can have a value of either 1 or 0. But its equivalent in a quantum system - the qubit (quantum bit) - can be both 1 and 0 at the same time. This phenomenon opens the door for multiple calculations to be performed simultaneously.

However, qubits need to be synchronised using a quantum effect known as entanglement, which Albert Einstein termed "spooky action at a distance".

There are four types of quantum computers currently being developed, which use:

  • Light particles
  • Trapped ions
  • Superconducting qubits
  • Nitrogen vacancy centres in diamonds


Quantum computers will enable a multitude of useful applications, such as being able to model many variations of a chemical reaction to discover new medications; developing new imaging technologies for healthcare to better detect problems in the body; or to speed up how we design batteries, new materials and flexible electronics."

 

Quantum Algorithms

 

[MIT]: "In quantum computing, it’s not just the computers themselves that are hard to build. They also need sophisticated quantum algorithms - specialized software that’s tailored to get the best out of the machines. Since the field of quantum computing is so new, only a small band of experts today can create advanced software that will work on the machines.

The excitement around quantum computers stems from the fact that instead of digital bits, which represent either 1 or 0, they use “qubits,” which can be in both states at once thanks to a phenomenon known as superposition. Another almost mystical quality, called entanglement, means that qubits can influence one another even if they’re not physically connected.

Adding extra qubits exponentially increases the computing power of quantum machines, which may soon be able to outperform even the top supercomputers at a limited range of tasks. That’s the good news; the not-so-good news is that qubits tend to lose their delicate quantum state after mere milliseconds. Changes in temperature, or even the tiniest of vibrations, can also disrupt them and throw errors into their calculations.

This is where quantum algorithms come in. They run a specific calculation on a quantum machine as quickly and efficiently as possible, and they can often help mitigate errors. “Think of it like tuning a guitar,” says Aspuru-Guzik. “Just as you adjust the strings so they’re in harmony, we can play with various parameters until a quantum circuit is tuned for a particular application.”"

 

 

 <More to come ..>


 

Document Actions