When will we have a quantum computer?. (May 2019)

• Record Type: Journal Article
• Authors: Dyakonov, M.I.
• Is Part Of: Solid-state electronics. Volume 155(2019)
• Page Start: 4
• Page End: 6
• Publication Date: 2019-05
• Subjects: Semiconductors -- Periodicals; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.sse.2019.03.004
• Languages: English
• ISSNs: 0038-1101

Abstract

Highlights: A classical computer with N bits at any given moment is in one of its possible 2 N states. In contrast, the state of the hypothetical quantum computer with N qubits is defined by the values of 2 N continuous parameters, the quantum amplitudes. To beat your laptop in performing some special tasks, like factoring very large numbers, one needs ∼1000 qubits. Accordingly, the number of continuous variables that should be under our control is at least 2 1000 ∼ 10 300 . Thus the answer to the question in the title is: as soon as physicists and engineers will learn to control thus number of degrees of freedom, which means NEVER .