The discussion around the wider proliferation of quantum computing tends to be of the half glass variety — but is it a glass half full or empty? A key stakeholder effected by this question and its answer are the fiber network providers charged with the rapid transfer of quantum’s large, complex, and fragile data loads. As advanced as they are, today’s fiber technology faces several challenges in playing its role to achieve quantum “at scale.”
Among these are engineered quantum-ready devices that would be needed to integrate with today’s existing fiber infrastructure. One example of this is low-loss fiber connectors that serve to minimize signal loss to maintain the integrity of quantum states during connection and disconnection. Another example is Dense Wavelength Division Multiplexing (DWDM) technology for the transmission of both classical and quantum signals over the same fiber and at the same time. DWDM secures the Quantum Key Distribution, ensuring only paired quantum connections can communicate.
Today, quantum networking is a combination of quantum entanglement using physical media to keep the states connected and secured. So, while Dark Fiber is the best solution for most Quantum networks, DWDM can also hold quantum parity in the event that fiber is unavailable.
Fiber’s Role in Ensuring a Reliable Quantum State
In any discussion of quantum computing, it is important to address the quantum state, which governs the behavior and information-carrying capacity of quantum systems. It distinguishes quantum mechanics from classical physics and provides the very essence of powerful technologies in quantum computing and communication. Fiber networks provide the highway needed to transport these quantum states. In doing so, these networks must offer the capability to transmit the fragile quantum bits (qubits) over long distances.
The complexity or fragility addressed here comes from the quantum state.
To better understand this, let’s return to our Pac-Man example. As you picture the game, recall the dots or power pellets laid out throughout the maze, which temporarily power Pac-Man over the ghosts. In the real world, when Pac-Man eats a power pellet, it’s gone. But in the quantum world, that pellet is far more complicated as it assumes various states of being, such as:
- Superposition: The power pellet isn’t just “there” or “not there.” Simultaneously, it’s both there and not there, like a ghostly, partially-eaten pellet. It exists in multiple “states” at once. Pac-Man wouldn’t know for sure if he could get it until he tried to eat it.
- Entanglement: Picture two power pellets that are linked together. What happens to one instantly affects the other, no matter how far apart they are. If Pac-Man tries to eat one and it “becomes” eaten, the other one also changes instantaneously, even if it’s on the other side of the maze. It’s like they’re talking to each other!
- Uncertainty: Pac-Man can’t know for sure the exact “state” of the pellet (both its “thereness” and its “readiness-to-be-eaten”) until he interacts with it. The act of observing or trying to eat it changes its state. Before he tries, it’s a bunch of possibilities. After, it’s just one.
- Fragility: The power pellet’s “quantum state” is very fragile. If a ghost gets too close, the delicate “both-there-and-not-there” state can collapse. The pellet becomes either fully “there” or fully “not there.”
For Pac-Man, quantum states are like power pellets that are spooky, connected, fuzzy, and easily disrupted. In the real world, the challenge is that this same fragility of quantum states can easily be disrupted when running on fiber over long distances. In this case, the use of advanced error correction techniques and quantum repeaters is needed to maintain a reliable quantum state.
From Challenges to Future Directions
Despite the challenges, there’s a promising outlook at the intersection of quantum computing and fiber optic networks. There is every expectation that quantum computing promises unprecedented processing power, and that fiber networks will provide its underlying infrastructure. Understanding this relationship reveals the potential for groundbreaking applications, such as:
- Quantum Internet – a network of interconnected quantum computers, sharing information and resources, which would require robust fiber networks to connect quantum processors, memories, and repeaters.
- Secure Communications – in a world increasingly concerned with data security, Quantum Key Distribution (QKD), a cryptographic protocol used by governments and financial institutions, utilizes quantum mechanics to generate shared secret keys. QKD relies on fiber networks to protect against cyber threats.
- Distributed Quantum Computing – would allow researchers to collaborate on complex problems by pooling resources to accelerate breakthroughs in drug discovery, materials science, and artificial intelligence.
- Quantum Sensing – can detect minute changes in magnetic fields, gravity, and other environmental factors with exceptional precision. Fiber networks can connect these sensors to central processing units, enabling real-time monitoring and analysis over large areas.
- Cloud Quantum Computing – connected through fiber networks would democratize access to quantum computing, allowing researchers and businesses to explore its potential without the need for expensive hardware.
Conclusion
With advancements in fiber network infrastructure along with the development of low-loss fiber connectors, DWDM technology, quantum repeaters, and other advancements, there’s reason to be optimistic about the many transformative applications of quantum computing at scale.
Underpinning these advancements will be robust fiber networks from FiberLight.