Quantum Entanglement Solves 250-Year-old Euler Puzzle in Spain

A mathematical puzzle that Leonhard Euler deemed unsolvable in the 1700s has been cracked using quantum entanglement, a breakthrough that could lead to more error-resistant quantum computers. In the 1700s, according to folklore, Russian Empress Catherine the Great posed a puzzle to the polymath Leonhard Euler. Could he find a way to arrange 36 military officers from six different regiments in a 6-by-6 grid so that in each row and each column, each officer belongs to a different rank and regiment?

Euler concluded that no such arrangement exists, and more than a century later another mathematician, Gaston Tarry, rigorously proved this to be correct. After another 100 years had passed, however, the '36 officers problem' got a second life. In 2022, Karol Życzkowski at Jagiellonian University in Poland and his colleagues showed that the problem could be solved after all – if it was made quantum.