https://www.scientificamerican.com/article/beyond-quantum-supremacy-the-hunt-for-useful-quantum-computers/ > Just occasionally, Alán Aspuru-Guzik has a movie-star moment, when fans half his age will stop him in the street. “They say, ‘Hey, we know who you are’,” he laughs. “Then they tell me that they also have a quantum start-up, and would love to talk to me about it.” He doesn’t mind a bit. “I don’t usually have time to talk, but I’m always happy to give them some tips.” > That affable approach is not uncommon in the quantum-computing community, says Aspuru-Guzik, who is a computer scientist at the University of Toronto, Canada, and co-founder of quantum-computing company Zapata Computing in Cambridge, Massachusetts. Although grand claims have been made about a looming revolution in computing, and private investment has been flowing into quantum technology, it is still early days, and no one is sure whether it is even possible to build a useful quantum computer.