A research team led by Osaka University demonstrated how information encoded in the circular polarization of a laser beam can be translated into the spin state of an electron in a quantum dot, each being a quantum bit and a quantum computer candidate. The achievement represents a major step towards a “quantum internet,” in which future computers can rapidly and securely send and receive quantum information.
Quantum computers have the potential to vastly outperform current systems because they work in a fundamentally different way. Instead of processing discrete ones and zeros, quantum information, whether stored in electron spins or transmitted by laser photons, can be in a superposition of multiple states simultaneously. Moreover, the states of two or more objects can become entangled, so that the status of one cannot be completely described without this other. Handling entangled states allow quantum computers to evaluate many possibilities simultaneously, as well as transmit information from place to place immune from eavesdropping.
However, these entangled states can be very fragile, lasting only microseconds before losing coherence. To realize the goal of a quantum internet, over which coherent light signals can relay quantum information, these signals must be able to interact with electron spins inside distant computers.
Researchers led by Osaka University used laser light to send quantum information to a quantum dot by altering the spin state of a single electron trapped there. While electrons don’t spin in the usual sense, they do have angular momentum, which can be flipped when absorbing circularly polarized laser light.
“Importantly, this action allowed us to read the state of the electron after applying the laser light to confirm that it was in the correct spin state,” says first author Takafumi Fujita. “Our readout method used the Pauli exclusion principle, which prohibits two electrons from occupying the exact same state. On the tiny quantum dot, there is only enough space for the electron to pass the so-called Pauli spin blockade if it has the correct spin.”
Quantum information transfer has already been used for cryptographic purposes. “The transfer of superposition states or entangled states allows for completely secure quantum key distribution,” senior author Akira Oiwa says. “This is because any attempt to intercept the signal automatically destroys the superposition, making it impossible to listen in without being detected.”
The rapid optical manipulation of individual spins is a promising method for producing a quantum nano-scale general computing platform. An exciting possibility is that future computers may be able to leverage this method for many other applications, including optimization and chemical simulations.
The Latest on: Quantum internet
via Google News
The Latest on: Quantum internet
- Dream 11, Mobile Premier League, Paytm, Infoedge, MakeMyTrip, HDFC Life to Titan - Internet companies focussed on Digital Transformation | Jefferies highlightson December 1, 2020 at 12:55 am
India has a fast-growing mobile internet base, with more than 650 mn mobile broadband subscribers and 100 mn broadband subscribers added last year. Smartphone penetration, too, is healthy, at 50% of ...
- IBM Cloud Announces Quantum-Safe Cryptography to Protect Data in the Hybrid Eraon November 30, 2020 at 8:35 am
IBM today announced a series of cloud services and technologies designed to help clients maintain the highest available ...
- IBM Cloud gets quantum-resistant cryptographyon November 30, 2020 at 7:05 am
IBM Corp. is looking to make enterprise workloads deployed on its public cloud resistant to tomorrow’s encryption-breaking quantum computers. As a first step to that end, the company today introduced ...
- IBM offers quantum-safe cryptography support for key management and app transactions in the cloudon November 30, 2020 at 6:34 am
IBM brings hybrid cloud leadership together with quantum and security research expertise to stay at the forefront of quantum cybersecurity.
- IBM Cloud Delivers Quantum-Safe Cryptography and Hyper Protect Crypto Services to Help Protect Data in the Hybrid Eraon November 30, 2020 at 4:05 am
PRNewswire/ -- IBM (NYSE: IBM) today announced a series of cloud services and technologies designed to help clients maintain the highest available level ...
- Indian-led research team brings quantum internet closer to realityon November 28, 2020 at 3:40 pm
When someone breaks into a transmission and tries to intercept it — the message is destroyed. That’s the quantum internet, which builds on the laws governing quantum mechanics, with the promise of ...
- QuTech, KPN, SURF and OPNT join forces to build a quantum networkon November 26, 2020 at 10:02 am
The project will focus on connecting different quantum processors, a significant distance apart, over a Dutch network.
- Xanadu, MaRS, Creative Destruction Lab launch Canada’s first quantum networkon November 26, 2020 at 8:36 am
Toronto-based quantum computing startup Xanadu, in partnership with MaRS and Creative Destruction Lab (CDL), announced the launch of a new quantum network.
- Quantum computing: Aliro wants to make quantum hardware more accessible for software developers and network engineerson November 24, 2020 at 5:00 pm
With Q.COMPUTE and Q.NETWORK, Aliro Quantum is using cloud tech to make it easy for software developers to run quantum programs and networking engineers to build quantum networks.
- Quantum Integration's IoT Platform Proves to Be the Ideal Solution for Electronics Hobbyistson November 24, 2020 at 10:03 am
Quantum Integration, following a successful Kickstarter campaign for its complete Internet of Things (IoT) platform for hobby enthusiasts, ...
via Bing News