Qubit’s Own Electric Current Could Offer a Simpler Readout Method

A new study with support from FAPESP proposes circumventing this problem by utilizing a unique property of a certain type of qubit called an “Andreev qubit.”

According to the authors, this method could eliminate the need for ancillas, auxiliary qubits used in current techniques for non-destructive quantum readout.

In many of these protocols, the qubit’s information is transferred to an auxiliary quantum system called an ancilla.

These states, known as “Andreev states,” are produced by this process and confined to the nanoscale region separating two superconducting materials.

A signature of the quantum state Any qubit state can be geometrically represented by a point on the so-called “Bloch sphere.”