Quantum computers that are “practically useful” are 5-to-10 years away, Google Chief Executive Officer Sundar Pichai said, comparing the groundbreaking technology to where artificial intelligence was about a decade ago.

Google claims quantum computing could see real-world applications within five years, sparking debate among experts worldwide.

QuEra Computing, a Boston-based quantum computing company, has raised $230 million in a round led by Google (GOOGL) and SoftBank (SFTBF) ’s Vision Fund 2 to develop “fault-tolerant” quantum computers, designed to overcome the computational errors that have long hindered real-world quantum applications.