RSS icon
Twitter icon
Facebook icon
Vimeo icon
YouTube icon


Quantum bits, or “qubits,” are the quantum-mechanical analogue of the minimum information unit in a classical computer. A conventional electronic binary digit, abbreviated “bit,” can have only one of two values: on or off, 0 or 1, as represented by electrical charges, voltages or magnetization. A quantum bit, however, can be 0, 1, or a “superposition” of both at once, owing to the inherently indeterminate nature of unmeasured quantum states.

Examples include photon qubits, whose orientation can be a superposition of  horizontal and vertical polarization;  electron spin qubit, where the two states are spin-up and spin-down orientations of the electron’s spin; flux qubit, where the two states correspond to two magnetic flux values in a Josephson junction.

There is currently no content classified with this term.

Subscribe to A Quantum Bit 

Quantum physics began with revolutionary discoveries in the early twentieth century and continues to be central in today’s physics research. Learn about quantum physics, bit by bit. From definitions to the latest research, this is your portal. Subscribe to receive regular emails from the quantum world. Previous Issues...

Sign Up Now

Sign up to receive A Quantum Bit in your email!

 Have an idea for A Quantum Bit? Submit your suggestions to