Bidirectional wavelength tuning of individual semiconductor quantum dots in a flexible rolled-up microtube

We consider a pair of artificial atoms with different ground-state energies. By means of finite element calculations, we predict that the ground-state energies can be tuned into resonance if the artificial atoms are placed into a flexible ring structure, which is elastically deformed by an external force. This concept is experimentally verified by embedding self-assembled quantum dots with low density into the wall of a rolled-up microtube ring resonator. We demonstrate that quantum dots can elastically be tuned in and out of resonance with each other or with the ring resonator modes.