Scientists have created a working quantum computer inside a diamond that includes protection against decoherence noise that prevents it from functioning properly.
A team of international scientists working from several universities have been able to create a fully functional 2 qubit quantum computer inside of a diamond.
The results of their study, published in today’s Nature Journal, shows they have been able to use their computer to run an implementation of Grover’s algorithm to find an entry in an unsorted database with a 95% success rate.
The current technology offers major improvements over other quantum computing technologies for several reasons.
Scientists say that their quantum qubit circuits are completely scalable unlike many other quantum implementations.
Another benefit is the high strength of the bonds within a diamond offer protection from ‘natural noise’, called decoherence, that interferes with other quantum computers.
To protect against coherence other implementations are housed within very large containers that are super-cooled while the diamond implementation eliminates the need for such expensive set ups.
The circuit built inside of the diamond also uses atomic particles to perform calculations by using electromagnetic pulses to control the spin of sub-atomic particles.
Specifically used the nucleus of a nitrogen atom and an electron, both trapped inside of the diamond, as qubits for the quantum calculations.
Scientists say that using the nuclei of an atom also offers better protection against decoherence that electron based implementations are much more prone to.
The nuclei based circuits work slower than the highly theoretical pure electron based system but promise to offer phenomenal speed increases over magnetic bases system that replicate the behavior of atomic particles, such as the D-Wave system.
D-Wave currently is building a 512 qubit quantum computer that skeptics say isn’t a “real” quantum computer because it doesn’t use atomic particles for quantum calculations.
Regardless of the skeptics, Department of Defense contractors and companies like Google currently are in contracts to use the D-Wave system.
If researches can scale out the diamond based circuits as they say, we will enter a new era of computing – one with a fully aware all-knowing true artificial intelligence computing system.
The current
Press TV reports:
Press TV – Researchers of the University of Southern California, Iowa State University, University of California, Santa Barbara, and Delft University of Technology in the Netherlands used the diamond to create a protocol for controlling quantum information.
Although the tiny system is not very powerful and only has two qubits, it shows the viability of producing functioning solid-state quantum computers.
Instead of using electrons as the qubits, researchers used nitrogen nuclei, from the diamond’s imperfections. The spin in a rogue nitrogen nucleus became the first qubit, with an electron in a second flaw forming the second.
Although a nucleus is a slower qubit than an electron, it is much more stable.
Electrons are smaller than nuclei and perform computations much more quickly, but they fall victim more quickly to decoherence, scientists noted.
“A nucleus has a long decoherence time – in the milliseconds,” said Professor Daniel Lidar of the University of Southern California. “You can think of it as very sluggish.”
Traditional computer bits can encode either a one or a zero but qubits can encode a one and a zero at the same time. This property, called superposition, along with the ability of quantum states to “tunnel” through energy barriers, will someday allow quantum computers to perform optimization calculations much faster than traditional computers.
“It’s a little like time travel” because switching the direction of rotation time-reverses the inconsistencies in motion as the qubits move back to their original position, added Lidar.
The team demonstrated their novel computer’s quantum operation by seeing how closely it matched Grover’s algorithm, a test consisting of a search of an unsorted database.
“This demonstration of performing a quantum algorithm at the subatomic level with single spins suggests a pathway to build increasingly complex quantum machines, using qubit control protocols that circumvent the expected limitations from real materials,” explained David Awschalom of the University of California, Santa Barbara.
The TG Daily reports:
Working quantum computer built inside a diamond
A quantum computer created inside a diamond is the first of its kind to include protection against ‘decoherence’ – noise that prevents it from functioning properly.
The team used the diamond’s impurities to create the computer’s two qubits. The spin in a rogue nitrogen nucleus became the first qubit, with an electron in a second flaw forming the second.
Electrons are smaller than nuclei and perform computations much more quickly, but also fall victim more quickly to decoherence. A qubit based on a nucleus is much more stable, but slower.
[…]The team was able to demonstrate that their diamond-encased system does indeed operate in a quantum fashion by seeing how closely it matched Grover’s algorithm – a test consisting of a search of an unsorted database.
Because a quantum computer has the advantage of superposition, it can find the correct answer more quickly. While a standard search would get the right answer half the time, a quantum computer searching through an unsorted list of four choices will find the correct choice on the first try, every time.
[…]
Source: TG Daily
From Phys.org:
Quantum computer built inside a diamond
The demonstration shows the viability of solid-state quantum computers, which – unlike earlier gas- and liquid-state systems – may represent the future of quantum computing because they can be easily scaled up in size. Current quantum computers are typically very small and – though impressive – cannot yet compete with the speed of larger, traditional computers.
The multinational team included USC Professor Daniel Lidar and USC postdoctoral researcher Zhihui Wang, as well as researchers from the Delft University of Technology in the Netherlands, Iowa State University and the University of California, Santa Barbara. Their findings will be published on April 5 in Nature.
The team’s diamond quantum computer system featured two quantum bits (called “qubits”), made of subatomic particles.
[…]Though solid-state computing systems have existed before, this was the first to incorporate decoherence protection – using microwave pulses to continually switch the direction of the electron spin rotation.
“It’s a little like time travel,” Lidar said, because switching the direction of rotation time-reverses the inconsistencies in motion as the qubits move back to their original position.
The team was able to demonstrate that their diamond-encased system does indeed operate in a quantum fashion by seeing how closely it matched “Grover’s algorithm.”
[…]
The test is a search of an unsorted database, akin to being told to search for a name in a phone book when you’ve only been given the phone number.
Sometimes you’d miraculously find it on the first try, other times you might have to search through the entire book to find it. If you did the search countless times, on average, you’d find the name you were looking for after searching through half of the phone book.
Mathematically, this can be expressed by saying you’d find the correct choice in X/2 tries – if X is the number of total choices you have to search through. So, with four choices total, you’ll find the correct one after two tries on average.
A quantum computer, using the properties of superposition, can find the correct choice much more quickly. The mathematics behind it are complicated, but in practical terms, a quantum computer searching through an unsorted list of four choices will find the correct choice on the first try, every time.
[…]
Source: Phys.Org