Circulating current in a qubit
Clockwise, anti-clockwise and superposition states are shown.
Schrodingerfs cat
Facing left and right and these superposition are shown. Can macroscopic scale object exhibit such superposition?
Quantum coherent oscillation
Quantum mechanical states are controlled by relative phase between two microwave pulses.


Fast control of qubit coherence with phase shift method

A superconductor ring with Josephson junctions behaves as a quantum 2-level system and is expected to be a candidate for a quantum bit (qubit), which is a key ingredient of a quantum computer. The size of the ring is about 10ƒÊm, which is much larger than atoms or molecules but it still shows quantum nature of the 2-level system. The quantum superposition in such a macroscopic scale object is sometimes called Schrodingerfs cat. (Page 36)