Related Post
Scientists have made a groundbreaking advancement by successfully transmitting both quantum and conventional data through a single optical fiber for the first time. This research illustrates that quantum data, represented by entangled photons, and traditional internet data, conveyed via laser pulses, can coexist within the same fiber-optic cable.
Historically, efforts to establish a quantum internet have primarily concentrated on the necessity for separate infrastructure or dedicated channels to prevent interference from classical data. However, this innovative hybrid network could significantly enhance the efficiency of quantum communications by allowing quantum and conventional data to share the same infrastructure. The findings of this pivotal study were published on July 26 in the journal Science Advances.
Fiber-optic cables are constructed from thin strands of glass or plastic fibers that transmit data as infrared light pulses. These fibers utilize different color channels, each corresponding to a unique wavelength of light, to carry data.
In previous research, scientists demonstrated that quantum data could be transmitted through standard fiber-optic cables. However, this new experiment marks a significant milestone as it is the first instance of both quantum and conventional data being transmitted simultaneously within the same color channel.
The creation of hybrid networks poses several challenges, primarily because quantum data is typically transmitted through fiber-optic cables using entangled photons. Entanglement occurs when two qubits—the fundamental units of quantum information—are interconnected in such a manner that information can be shared between them, irrespective of their spatial or temporal separation. Nonetheless, this entangled state is remarkably fragile and can be easily disrupted by environmental factors, including noise and interference from other signals. Such disruptions, particularly from data sharing the same wavelength on a fiber-optic channel, can lead to a phenomenon known as “decoherence,” resulting in the loss of the quantum state and, consequently, data.
“To realize the quantum internet, we must transmit entangled photons through fiber-optic networks,” stated Michael Kues, co-author of the study and head of the Institute of Photonics at Leibniz University Hannover. “At the same time, we aim to continue utilizing optical fibers for conventional data transmission.”
To overcome these challenges, the researchers employed a technique known as electro-optic phase modulation, which allowed them to precisely adjust the frequency of the laser pulses to align with the color of the entangled photons. This synchronization enabled the simultaneous transmission of both data types within the same color channel without disrupting the quantum information carried by the entangled photons.
The ability to transmit quantum and conventional data in the same channel effectively frees up other color channels within the fiber-optic cable for additional data. This advancement is crucial for the practical and scalable application of quantum computing technologies, such as ultra-secure communications and quantum cryptography.
“Our research represents a significant step toward integrating the conventional internet with the quantum internet,” Kues remarked. “Our experiment illustrates the feasibility of implementing hybrid networks in practice.”
