The quantum computers use atoms (quanta) as its physical system. Unlike in regular computing where the information is carried in either 0 or 1 bit, the quantum mechanics allows an atom to be in both 0 and 1 state simultaneously. This bit of data is called a qubit.
So, as per the theory, if there are equal number of qubits and the regular bits, then the qubits will hold twice the information, i.e. if there are n qubits in the supercomputer, then it will have 2^n different states. So experimentally, it can hold more information as compared to regular digital bits thereby increasing the speed of the system exponentially.
China is set to complete the installation of the world’s longest quantum communication network stretching 2,000km (1,240miles) from Beijing to Shanghai by 2016, say scientists leading the project. Quantum communications technology is considered to be “unhackable” and allows data to be transferred at the speed of light.
By 2030, the Chinese network would be extended worldwide, the South China Morning Post reported. It would make the country the first major power to publish a detailed schedule to put the technology into extensive, large-scale use.
The development of quantum communication technology has accelerated in the last five years. The technology works by two people sharing a message which is encrypted by a secret key made up of quantum particles, such as polarized photons. If a third person tries to intercept the photons by copying the secret key as it travels through the network, then the eavesdropper will be revealed by virtue of the laws of quantum mechanics – which dictate that the act of interfering with the network affects the behavior of the key in an unpredictable manner.
If all goes to schedule, China would be the first country to put a quantum communications quantum communications satellite in orbit, The satellite would be used to transmit encoded data through a method called quantum key distribution (QKD), which relies on cryptographic keys transmitted via light pulse signals. QKD is said to be nearly impossible to hack, since any attempted eavesdropping would change the quantum states and thus could be quickly detected by data-flow monitors.
It’s likely the technology initially will be used to transmit sensitive diplomatic, government policy and military information. Future applications could include secure transmissions of personal and financial data.
The country is also working to configure the new technology for civilian use. A pilot quantum-communications network that took 18 months to build was completed in February 2012 in Hefei. The network, which cost the city’s government 60 million yuan ($9.6 million), was designed by Pan’s team to link 40 telephones and 16 video cameras installed at city government agencies, military units, financial institutions and health-care offices.