Charge and Hybrid Qubits in 22nm FDSOI process

A number of recent studies report the achievements of silicon-based qubits. Furthermore, the benefits of nanometer-scale CMOS technologies boost the potential of miniaturization, scalability and full system integration for quantum computers. This abstract presents the recent development of a quantum system-on-a-chip utilizing quantum structures fabricated in 22nm FDSOI. The main challenge of achieving deep cryogenic operation for the mixed-signal classic circuit controlling the quantum core was surpassed by using programmable local heating DACs that slightly boost the local temperature of the die, which needs to be maintained around 4 K. A staged multi-phase operation was adopted for the digital core in order to minimize the quantum decoherence originated in digital noise injection.

We show that the fabricated quantum structures can be used to realize charge and/or hybrid qubits. The theoretical analysis and modeling of qubits are based on a Hubbard model in the tight-binding limit. Different types of qubits (for instance, spin, charge or hybrid) have been examined. Various topologies of interacting qubits are investigated exhibiting maximally entangled states. Preliminary experimental results are also presented.