Simulations suggest that one type of qubit could reveal its state through its own electric current, helping researchers monitor quantum computers with less disturbance and fewer components.

Like a bit in an ordinary computer, a qubit stores information using states labeled 0 and 1. A qubit can also be prepared in a superposition, a quantum combination of the two. These states belong to a physical system that researchers build and control. In the design explored here, that system is a tiny wire connected to superconducting materials.

The aim of quantum computing is to use quantum behavior to perform certain calculations more efficiently than conventional computers. That requires control: researchers must prepare qubits and change their states deliberately. Unwanted interactions with the surroundings can disrupt them, and measuring a qubit can alter it, too.