Machine learning in quantum spaces

Machine learning and quantum computing have their staggering levels of technology hype in common. But certain aspects of their mathematical foundations are also strikingly similar. In a paper in Nature, Havlíček et al.1 exploit this link to show how today's quantum computers can, in principle, be used to learn from data -- by mapping data into the space in which only quantum states exist. One of the first things one learns about quantum computers is that these machines are extremely difficult to simulate on a classical computer such as a desktop PC. In other words, classical computers cannot be used to obtain the results of a quantum computation.