Flying qubits can turn the next page in quantum communication.

 

"Figure 1. The signal photon, manipulated by the integrated photonic circuit, creates a 4D qudit represented by the set of orange spheres. Meanwhile, the idler photon, represented by the blue sphere, acts as a remote control for the signal photon." (ScitechDaily, Flying Qudits: Unlocking New Dimensions of Quantum Communication)

"Credit: Haoqi Zhao, Yichi Zhang, Zihe Gao, Jieun Yim, Shuang Wu, Natalia M. Litchinitser, Li Ge, and Liang Feng, edited" (Scitech, Flying Qudits: Unlocking New Dimensions of Quantum Communication)

Flying qubits give a new dimension to quantum computing and communication. The qubit hovers above the circuit that transmits information into it. The system's base is in the photonic circuit, and the 4D qubit can operate in many states. 

In those systems, the qubits can travel on tracks. Then, they can exchange information between photonic circuits. And that makes them more effective than traditional qubits. 

When the quantum system sends data, the receiving system must know the energy levels or states. That the transmitter uses. The system can use fixed states. Or it can use variable states in data transmission. The system can also mix information bites to random states. But the problem is this: the receiver must know those states. It can sort the data in the original order. 

The system can also equip data bites with serial numbers. That allows the receiver to sort them into the right order. The long-range quantum communication allows the quantum computers to communicate with other quantum computers using quantum states. That makes the data handling process more effective. 

"Figure 2. (a) The experimentally retrieved (upper row) and theoretically predicted (lower row) density matrices of two selected quantum states. (b) Theoretically (left panel) and experimentally retrieved (right panel) probability-of-detection matrix. Credit: Haoqi Zhao, Yichi Zhang, Zihe Gao, Jieun Yim, Shuang Wu, Natalia M. Litchinitser, Li Ge, and Liang Feng" (ScitechDaily, Flying Qudits: Unlocking New Dimensions of Quantum Communication)

The regular data network can also transport quantum information. Each data package must contain information that states the quantum system used when it sent the package to the net. And, of course, the system requires a serial number of the data package. That receiving system can sort data in the right order. 

The reason why quantum networks are required is data security. But another thing is error detection in quantum computers. The quantum computer is the most powerful calculation system in the world. The only system that can make the error detection in a quantum computer system is another quantum computer. 

If those two quantum computers are too close to each other, that can cause a situation where the same outcoming effect can disturb both quantum computers.

This kind of system can add new dimensions to quantum communication and quantum computing. Quantum networks and quantum computers operate similarly. They just put data travel in lines. The communication that happens using quantum states is very hard for eavesdroppers. Data travels in physical wire in quantum communication. 

The qubit base is in the superposition between objects. The state of the qubit means the energy level. When the transmitter sends data to a receiver, that data travels between certain states. If somebody steals data, that decreases energy level. 

And that changes the qubit's state. In this case, the quantum computer loses data. Even if eavesdroppers can steal data, the computer sees that when the energy level differs from predicted states. 

https://scitechdaily.com/flying-qudits-unlocking-new-dimensions-of-quantum-communication/