Cavity QED with hybrid quantum-dot donor systems*

Nuclear spins are promising for quantum information applications due to their long coherence times. However, the underlying good isolation from the environment is a challenge for readout and the implementation of mutual interactions between them. 

A hybrid system in which an electron is shared between a quantum dot and ³¹P donor atom implementing a electron spin-nuclear spin flip-flop qubit has been realized. Employing ac-magnetic fields, this system can be harnessed to couple the nuclear spin to microwave cavity photons [1,2]. A related system with an electron confined in a double quantum dot and subject to a magnetic field gradient constitutes a flopping mode electron spin qubit that couples to cavity photons by electrical means [3,4]. 

We envision an architecture combining the key ideas of the two aforementioned systems and theoretically investigate the interaction between a nuclear spin with a microwave cavity by electrical means and thereby demonstrate nuclear spin readout [5] and explore further quantum information applications. 

[1] Tosi et al., PRB 98, 075131 (2018)

[2] Tosi et al., Nature Comm. 8, 450 (2017) 

[3] Benito et al., PRB 96, 235434 (2017)

[4] Mi et al., Nature 555, 7698 (2018)

[5] Mielke et al., PRX Quantum 2, 020347 (2021)