A new superinductor created within a silicon integrated circuit
A recent study published in Nature Electronics and carried out by researchers from nanoGUNE’s Quantum Hardware research group, Quantum Motion, London Centre for Nanotechnology, Imperial College London and the University of Cambridge introduces a new superinductor created within a silicon integrated circuit fabricated in a commercial complementary metal–oxide–semiconductor (CMOS) process.
Superinductors are electrical inductors that are engineered to have an extremely large inductance, often far beyond what can be achieved with conventional coils. They are particularly important for superconducting qubits and quantum circuits, as a large inductance can dramatically alter the circuit's quantum behaviour. This makes superinductors interesting for quantum technology, as they enable the creation of circuits with very large impedance and very small inductive energy scales.
In this work, researchers show that superconducting circuit elements can be fabricated with a commercial CMOS process by utilizing the Titanium nitride (TiN), TiN is particularly well suited for this purpose because of its high kinetic inductance, which makes it possible to create compact, high-inductance circuit elements while maintaining robust superconducting properties.
The work has reported the development of non-linear superinductor within a silicon integrated circuit. The system can be used to create a radiofrequency single-electron transistor — a widely used sensor for semiconductor spin qubits — with compact footprint and high sensitivity. The next step will be to integrate the resonator with multi-gate transistors to demonstrate high-speed high-fidelity spin readout well below the microsecond timescale. However, according to the research team, “the applications of the TiN-based CMOS inductors could expand well beyond quantum sensing and computing for spin qubits, impacting areas such as radio-astronomy, low-power cryoelectronics and quantum sensing and simulations”.