Quantum Optics Seminar: Dorian Gangloff

Combining highly coherent spin control with efficient coupling to single photons is a key building block for many protocols in quantum networks and quantum computing. On the one hand, optically active semiconductor quantum dots have unparalleled photonic properties, but have been limited to modest spin coherence by their resident nuclei. Here, I will describe both materials design [1] and active control techniques [2,3] that can be used to mitigate and even harness the effects of nuclei. On the other hand, diamond emitters such as the nitrogen-vacancy center are long-lived hosts of spin-based quantum information, but have limited photonic coherence. Here, I will describe how a new generation of emitters in diamond, based on group IV elements (Si, Ge, Sn), could provide the best of both worlds. I will show experimental results pertaining to all-optical control of the Sn qubit in diamond [4] and its photon coherence in a nanostructure [5]. These findings demonstrate that some of the most punishing material science challenges have a remedy, and constitute the basis for highly coherent spin-photon interfaces.

 

[1] Zaporski et al (2023) Nature Nano 18 (3), 257-263

[2] Jackson et al (2022) Phys Rev X 12 (3), 031014

[3] Zaporski et al (2023) arXiv:2301.10258

[4] Debroux et al (2021) Phys Rev X 11 (4), 041041

[5] Arjona-Martinez et al (2022) Phys Rev Lett 129 (17), 173603