Hole spin-orbit qubits: physics, materials, architectures and scalability prospects

Hole spins in semiconductor quantum dots have emerged as a promising candidate for the realization of scalable spin-qubit architectures. On the one hand, their intrinsic spin-orbit coupling enables electric-field driven spin resonance [1] as well as strong coupling to the photonic modes of superconducting microwave resonators [2]. On the other hand, spin-orbit coupling leads to unwanted variability in the qubit properties and susceptibility to charge noise. Managing these pros and cons is therefore key to the development of scalable quantum processors. Recent theoretical and experimental studies digging deep into hole-spin physics have revealed the existence of optimal operation regimes simultaneously maximizing electric driving efficiency and minimizing the impact of charge noise, with corresponding enhancement of qubit coherence. It was also shown that qubit variability can be largely counteracted by local electrostatic tuning. In this talk I will discuss these advances [3,4] as well as recently emerged opportunities coming from charge-mediated coupling to rf resonators [5]. I will then conclude with an outlook on scalable architectures based on hole spin qubits.

References:

1. Crippa et al., Phys. Rev. Lett. 120, 137702 (2018).

2. Yu et al., Nat. Nanotechnol. 18, 741 (2023).

3. Mauro et al., Phys. Rev. B 109, 155406 (2024).

4. Bassi et al., arXiv:2412.13069.

5. Champain et al., arXiv:2410.20217.