Quantum teleportation’s potential to be used in a wide variety of practical applications makes it a priority for many scientists and researchers. After years of development, a team of scientists finally made a significant breakthrough.
Via quantum entanglement and classical communication, quantum teleportation allows for the transfer of quantum information across large distances. Unfortunately, while there have been many successful quantum teleportation cases there hasn’t yet been a system whose rate can reach the order of Hertz.
Recently however, in a paper published in Light Science & Application, a team of scientists from the University of Electronic Science and Technology of China (UESTC) led by Professors Guangcan Guo and Qiang Zhou in cooperation with Professor Lixing You from the Shanghai Institute of Microsystem and Information Technology of the Chinese Academy of Sciences, have improved the teleportation rate to 7.1 cubits per second for the first time. This is a new record for the quantum teleportation system over a metropolitan range.
A successful demonstration outside the lab
Prof. Qiang Zhou said, “demonstrating high-speed quantum teleportation outside of a laboratory involves a whole set of challenges. This experiment shows how these challenges can be overcome and hence it establishes an important milestone towards the future quantum internet.” [1]
When it comes to real-world quantum teleportation systems, the main experimental challenge is performing the Bell state measurement (BSM). This can be boiled down to photons A & B, sometimes called Alice and Bob’s photons, to be indistinguishable from photon C, sometimes called Charlie, after being transmitted through fiber over long-distance.
The team created a fully running feedback system that caused the fast stabilization of the path length difference and photon polarization in order to achieve this. They also used a single piece of fiber-pigtailed periodically poled lithium niobate waveguide to create the entangled photon pairs, along with a high-quality quantum entangled light source with a 500 MHz repetition rate that was developed specifically for the teleportation system. [2]
This quantum teleportation system was high-speed and based on quantum optics, therefore requiring incredibly sensitive photon sensors to collect as many events as possible. In this experiment, the team used high-performance superconducting nanowire single-photon detectors.
These detectors provided such excellent efficiency and made nearly no noise, and so high-efficiency BSM and quantum state analysis were achieved. [3]
Positive results
Using both decoy-state methods and quantum state tomography to calculate teleportation fidelities, the team found that their results were well above the classical limit (66.7%) and confirmed that they had indeed achieved high-speed metropolitan quantum teleportation.
This “No.1 Metropolitan Quantum Internet of UESTC” is expected to progress toward a “high speed, high fidelity, multi-users, long-distance” quantum internet infrastructure someday. Doing so will involve combining quantum information nodes, integrated quantum light sources, and quantum repeaters. [4]
The team also predicts that this infrastructure will help make the quantum internet practical and applicable.
Potential applications: quantum internet, computers, and more
The quantum internet tops the list for potential applications of quantum teleportation in the real world. If achieved, it would provide ultra-secure communications and enable the distribution of information worldwide. Quantum computers could be connected, creating a network of quantum nodes across which secure data transmissions could be instantly distributed across long distances.
Similarly, using photons as quantum carriers, it’s possible to establish secure quantum key distribution, guaranteeing encryption keys that are truly third-party proof.
There are many other ways that quantum teleportation could be woven into everyday life. Another to note is in metrology.
Quantum sensors and metrology devices could see improved sensitivity and precision. Quantum-enhanced measurements could be accomplished by teleporting quantum states of particles, like atoms or photons, and possibly improve gravimetric, magnetometric, and timekeeping measurements.
And yet, likely to the disappointment of many, there is no current understanding of how to achieve quantum teleportation for humans. Quantum physics has seen some fascinating developments however, that do suggest there may be a different type of teleportation available at some point in the future.
Human teleportation?
The kind of quantum teleportation that can be used for data in a quantum internet isn’t applicable to humans, but some theorize that the door to teleportation isn’t definitively closed to humans (yet).
At least theoretically, some scientists believe that a form of teleportation that involved deconstructing the physical body (or even object) at one location, then transmitting precise and accurate information about the pattern of that physical body to the destination, and then reconstructing the body based on that information, would be possible.
However, this would be a vast amount of information and the challenges and limitations associated with completing such a process are far beyond what science is currently capable of. Not only are there unthinkably complex problems concerning the scanning, encoding, and transmitting of such large amounts of information reliably, accurately, and precisely, but there are also numerous issues concerning the preservation of consciousness and identity during the process.
It’s uncertain at this point in time whether teleportation will ever be a viable mode of transportation, even with the leaps and bounds that have been made in recent years. Until there’s more information to achieve a definite answer, there remains excitement about a much closer goal – the quantum internet.
Sources
[1] – [4]
