A Superconducting Qubit that protects itself

A new qubit design combines a gyrator with superconducting circuits to intrinsically protect the qubit from noise. (APS/Carin Cain)

Physicists from RWTH Aachen University in Germany have proposed what’s known as a ‘synthetic magnetic field‘, which they think could help protect the fragile qubits.

They have designed a circuit composed of state-of-the-art superconducting circuit elements and a nonreciprocal device, that can be used to passively implement the GKP quantum error-correcting code.

Back in 2001, a trio of researchers – Daniel Gottesman, Alexeir Kitaev, and John Preskill – formulated a way to encode this kind of protection into a space as an intrinsic feature of the circuitry holding the qubits, potentially allowing for slimmer hardware. It became known as the Gottesman-Kitaev-Preskill (GKP) code. But the GKP code relied on confining an electron to just two dimensions using intense, large magnetic fields in a way that just isn’t practical. 

The team at RWTH has suggested replacing the impossibly large magnetic field with a superconducting circuit comprising of components that serve much the same purpose, ironing out the noise. (ScienceAlert)

Anja Metelmann at APS Physics does a top job of going through them step-by-step for those eager for details.

This research was published in Physical Review X.