A team of scientists at the Vienna University of Technology (TU Wien; Vienna, Austria) has demonstrated that light can be slowed down in an optical fiber. By coupling atoms to glass fibers light was slowed down to a speed of 180 km/h. The team even managed to bring the light to a complete stop and to retrieve it again later. This technology is an important prerequisite for a future glass-fiber-based quantum Internet, in which quantum information can be teleported over great distances.
New results represent an important step toward long-distance quantum communication.
A new study extends the range of fiber-based quantum communications beyond 600km for the first time. Scientists implemented a new signal stabilization technique and used the twin-field quantum key distribution (QKD) protocol.
Mirko Pittaluga from Toshiba Europe Limited and the University of Leeds said, “This will allow us to build national and continental scale fiber networks connecting major metropolitan areas. Together with satellite links, we can now envisage truly global quantum networks.”
NATO cybersecurity center finishes tests of quantum-proof network https://www.zdnet.com/article/nato-cybersecurity-center-finishes-tests-of-quantum-proof-network/
The NATO Cyber Security Centre (NCSC) has completed its test run of secure communication flows that could withstand attackers using quantum computing. Konrad Wrona, principal scientist at the NCSC, told ZDNet that it is becoming increasingly important to create protection schemes against current and future threats. “Securing NATO’s communications for the quantum era is paramount to our ability to operate effectively without fear of interception,” Wrona said.
Quantum signals may possess a number of advantages over regular forms of communication, leading scientists to wonder if humanity was not alone in discovering such benefits. Now a new study suggests that, for hypothetical extraterrestrial civilizations, quantum transmissions using X-rays may be possible across interstellar distances.
Quantum communication relies on a quantum phenomenon known as entanglement. Essentially, two or more particles such as photons that get “linked” via entanglement can, in theory, influence each other instantly no matter how far apart they are.
Entanglement is essential to quantum teleportation, in which data can essentially disappear one place and reappear someplace else. Since this information does not travel across the intervening space, there is no chance the information will be lost.
To accomplish quantum teleportation, one would first entangle two photons. Then, one of the photons—the one to be teleported—is kept at one location while the other is beamed to whatever destination is desired.
Next, the photon at the destination’s quantum state—which defines its key characteristics—is analyzed, an act that also destroys its quantum state.
“If photons in Earth’s atmosphere don’t decohere to 100 km, then in interstellar space where the medium is much less dense then our atmosphere, photons won’t decohere up to even the size of the galaxy,” Berera says.
In the new study, the researchers investigated whether and how well quantum communication might survive interstellar distances. Quantum signals might face disruption from a number of factors, such as the gravitational pull of interstellar bodies, they note.
The scientists discovered the best quantum communication channels for interstellar messages are X-rays.
Kvanttitietokoneiden kehittyessä yksi tutkimuksen aiheita on se, miten kvanttikoneiden dataa voisi lähettää internetissä. Tällä hetkellä kvanttitieto on epävakaata, pitkien etäisyyksien päässä ja kvanttibitit eli kubitit katoavat helposti tai pirstoutuvat lähetyksen aikana.
Klassisia bittejä lähetetään nykyään valopulsseina kuituoptisten kaapeleiden yli. Signaaleja vahvistetaan toistimilla matkan varrella. Jotta kubitteja voisi lähettää samalla tavoin, tarvitaan laitteita, verkon yli riippumatta siitä, kuinka pitkälle datan on kuljettava.
Tällaisia laitteita on tutkittu Lontoon Imperial Collegessa, Southamptonin yliopistossa sekä Stuttgartin ja Wurzburgin yliopistoissa Saksassa. Tutkijat väittävät nyt lähettäneensä kubitteja ensimmäistä kertaa tavallisten valokuitukaapeleiden yli. Tulokset on julkaistu Scientific Advances -lehdessä.
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9 Comments
Tomi Engdahl says:
Atom-coupled optical fiber slows light to 180 km per hour
http://www.laserfocusworld.com/articles/2015/04/atom-coupled-optical-fiber-slows-light-to-180-km-per-hour.html?cmpid=EnlLFWApril212015
A team of scientists at the Vienna University of Technology (TU Wien; Vienna, Austria) has demonstrated that light can be slowed down in an optical fiber. By coupling atoms to glass fibers light was slowed down to a speed of 180 km/h. The team even managed to bring the light to a complete stop and to retrieve it again later. This technology is an important prerequisite for a future glass-fiber-based quantum Internet, in which quantum information can be teleported over great distances.
Tomi Engdahl says:
A World-First Multinode Network Just Took Us Closer to The Elusive Quantum Internet
https://www.livescience.com/three-node-quantum-network.html
Tomi Engdahl says:
New results represent an important step toward long-distance quantum communication.
Scientists achieved quantum communication over fiber more than 600 kilometers long
https://www.techexplorist.com/scientists-achieved-quantum-communication-over-fiber-600-kilometers-long/41951/
New results represent an important step toward long-distance quantum communication.
A new study extends the range of fiber-based quantum communications beyond 600km for the first time. Scientists implemented a new signal stabilization technique and used the twin-field quantum key distribution (QKD) protocol.
Mirko Pittaluga from Toshiba Europe Limited and the University of Leeds said, “This will allow us to build national and continental scale fiber networks connecting major metropolitan areas. Together with satellite links, we can now envisage truly global quantum networks.”
Tomi Engdahl says:
Quantum internet repeaters are already being built in laboratories – photons have been teleported to quantum memory
http://www.thespaceacademy.org/2021/11/quantum-internet-repeaters-are-already.html
Tomi Engdahl says:
NATO cybersecurity center finishes tests of quantum-proof network https://www.zdnet.com/article/nato-cybersecurity-center-finishes-tests-of-quantum-proof-network/
The NATO Cyber Security Centre (NCSC) has completed its test run of secure communication flows that could withstand attackers using quantum computing. Konrad Wrona, principal scientist at the NCSC, told ZDNet that it is becoming increasingly important to create protection schemes against current and future threats. “Securing NATO’s communications for the quantum era is paramount to our ability to operate effectively without fear of interception,” Wrona said.
Tomi Engdahl says:
http://pme.uchicago.edu/news/chicago-expands-and-activates-quantum-network-taking-steps-toward-secure-quantum-internet
Tomi Engdahl says:
X-Rays Could Carry Quantum Signals Across the Stars Hypothetical interstellar civilizations could employ such signals for lossless long-distance communication
https://spectrum.ieee.org/search-for-extraterrestrial-intelligence?share_id=7143358
Quantum signals may possess a number of advantages over regular forms of communication, leading scientists to wonder if humanity was not alone in discovering such benefits. Now a new study suggests that, for hypothetical extraterrestrial civilizations, quantum transmissions using X-rays may be possible across interstellar distances.
Quantum communication relies on a quantum phenomenon known as entanglement. Essentially, two or more particles such as photons that get “linked” via entanglement can, in theory, influence each other instantly no matter how far apart they are.
Entanglement is essential to quantum teleportation, in which data can essentially disappear one place and reappear someplace else. Since this information does not travel across the intervening space, there is no chance the information will be lost.
To accomplish quantum teleportation, one would first entangle two photons. Then, one of the photons—the one to be teleported—is kept at one location while the other is beamed to whatever destination is desired.
Next, the photon at the destination’s quantum state—which defines its key characteristics—is analyzed, an act that also destroys its quantum state.
“If photons in Earth’s atmosphere don’t decohere to 100 km, then in interstellar space where the medium is much less dense then our atmosphere, photons won’t decohere up to even the size of the galaxy,” Berera says.
In the new study, the researchers investigated whether and how well quantum communication might survive interstellar distances. Quantum signals might face disruption from a number of factors, such as the gravitational pull of interstellar bodies, they note.
The scientists discovered the best quantum communication channels for interstellar messages are X-rays.
Tomi Engdahl says:
New quantum light source paves the way to a quantum internet
https://www.nanowerk.com/nanotechnology-news2/newsid=61959.php
Tomi Engdahl says:
Kvanttidataa lähettiin kuidussa ensimmäistä kertaa
https://etn.fi/index.php/13-news/16358-kvanttidataa-laehettiin-kuidussa-ensimmaeistae-kertaa
Kvanttitietokoneiden kehittyessä yksi tutkimuksen aiheita on se, miten kvanttikoneiden dataa voisi lähettää internetissä. Tällä hetkellä kvanttitieto on epävakaata, pitkien etäisyyksien päässä ja kvanttibitit eli kubitit katoavat helposti tai pirstoutuvat lähetyksen aikana.
Klassisia bittejä lähetetään nykyään valopulsseina kuituoptisten kaapeleiden yli. Signaaleja vahvistetaan toistimilla matkan varrella. Jotta kubitteja voisi lähettää samalla tavoin, tarvitaan laitteita, verkon yli riippumatta siitä, kuinka pitkälle datan on kuljettava.
Tällaisia laitteita on tutkittu Lontoon Imperial Collegessa, Southamptonin yliopistossa sekä Stuttgartin ja Wurzburgin yliopistoissa Saksassa. Tutkijat väittävät nyt lähettäneensä kubitteja ensimmäistä kertaa tavallisten valokuitukaapeleiden yli. Tulokset on julkaistu Scientific Advances -lehdessä.