Applications #

We will be looking at certain applications of quantum entanglement. There are a few applications of quantum entanglement quantum cryptography, extremely precise clocks, quantum computers and improved microscopes.

Extremely precise clocks #

Look at your watch, and the time on your computer or phone. Chances are they may not display the same time. Even if they do, either you have calibrated your watch to prevent having too big an error or your watch requires a change of battery. This error can be the watch being faster or slower by a few minutes.

In recent years, there have been more resources allocated to developing extremely precise clocks. Why is this important? In our increasingly digitized world, many aspects of society, such as trading stock or GPS, will need to be accurate and synchronised for maximised profit and for the aid and functionality of driverless cars respectively.

A new type of clock is being developed called the quantum entanglement atomic clock. It will only be 0.1 seconds out of sync if it started running since the start of the universe. Atoms of ytterbium-171 are stored in close to absolute zero temperatures and trapped in optical captivity. Then a laser will shine at the atoms, causing them to undergo entanglement. A second laser will measure their average frequency, knowing that they can create a clock with absolute minimum error as atoms will remain at the same frequency for long periods.

Quantum computers #

Quantum computers are faster and able to solve more complex problems than the supercomputers of today. Ever since the introduction of computers, the processing units have become smaller and more efficient. Computers that took up a whole desk 30 years ago are less powerful than the phones in the palm of our hands. However, we are reaching the processing limits to these physical chips. The smallest units of information for supercomputers are bits, whereas quantum computers use qubits as smallest units of information. These qubits can be an electron spin or an electron charge or photons. (anything that is at least a 2-level quantum-mechanical system). Supercomputers, using 4 bits can store 1 of 16 different values. However, due to superposition where the value of the qubit is not known until measured, 4 qubits can store 16 different values. Using quantum entanglement, as each qubit is linked, every qubit added will double the number of values it can store. The qubits can react to a change in the value of other qubits regardless of how far they are apart, thus this allows them to store the 16 different values. More calculations can be run at once and in parallel. While the average person does not require the strength of quantum computing, this technology can be used for solving more complex problems and optimising the shipping routes in global supply chains.

Quantum cryptography #

Watch the following video¹ for a visual explanation to the BB84 protocol, one of the first and simplest quantum key distribution protocols!