Quantum positioning refers to a navigation system that records position with 1000 times more accuracy than anything before1. It can be divided into two categories: quantum active navigation system and quantum passive navigation system2.
Quantum superposition is a fundamental principle of quantum mechanics that states that linear combinations of solutions to the Schrödinger equation are also solutions of the Schrödinger equation. This follows from the fact that the Schrödinger equation is a linear differential equation in time and position.
The quantum active navigation system uses the method of transmitting and receiving quantum signals, and the positioning process usually uses satellite as the signal source2.
More precisely, the state of a system is given by a linear combination of all the eigenfunctions of the Schrödinger equation governing that system.
In quantum mechanics, a particle can be in a superposition of different states, and a measurement always finds it in one state.
The non-classical nature of the superposition process is brought out clearly if we consider the superposition of two states, A and B, such that there exists an observation which, when made on the system in state A, is certain to lead to one particular result, a say, and when made on the system in state B is certain to lead to some different result, b say.
What will be the result of the observation when made on the system in the superposed state? The answer is that the result will be sometimes a and sometimes b, according to a probability law depending on the relative weights of A and B in the superposition process. It will never be different from both a and b [i.e., either a or b]. The intermediate character of the state formed by superposition thus expresses itself through the probability of a particular result for an observation being intermediate between the corresponding probabilities for the original states, not through the result itself being intermediate between the corresponding results for the original states.
Chinese researchers, led by figures like Pan Jianwei, have made significant strides in quantum communication and computing. China is particularly advanced in quantum communication, building secure networks that use quantum key distribution (QKD), which is virtually unhackable. China has also launched quantum satellites, like Mozi and Jinan-1, to bolster its space-ground quantum network.
Quantum Technologies Explained
Quantum technologies are a loose set of nascent technologies that harness the principles of quantum mechanics to enable revolutionary breakthroughs across various fields. Quantum technologies can be grouped into three main areas—sensing, communication, and computing.
Quantum Sensing: I
n the field of quantum sensing, researchers are pushing to develop ultra-sensitive devices capable of measuring minute changes in motion and electromagnetic fields. As these technologies advance, they could lend unprecedented levels of precision to medical imaging and diagnosis, navigation, radar, geophysics, and more.
Quantum Communication:
Quantum communication promises to enable ultra-fast and highly secure data transmissions. With conventional electronics, data is typically encrypted and then sent as bits representing 1s and 0s. However, quantum bits—or qubits—can be transmitted in a state of superposition in which they can represent combinations of 1 and 0 simultaneously. This allows for virtually un-hackable communications—a highly sought after capability for governments, militaries, financial firms, and others.
Quantum Computing:
The third area of quantum technologies—quantum computing—has garnered the most attention globally and promises to be the most transformative of the three. Like quantum communication devices, quantum computers exploit the properties of superposition, which enables many calculations simultaneously. Theoretically, quantum computers equipped with enough qubits can perform complex calculations at speeds exponentially faster than even the most advanced supercomputers in use today.