  Deterministic sources of quantum light (i.e. single photons or pairs of
entangled photons) are required for a whole host of applications in quantum
technology, including quantum imaging, quantum cryptography and the
long-distance transfer of quantum information in future quantum networks.
Semiconductor quantum dots are ideal candidates for solid-state quantum
emitters as these artificial atoms have large dipole moments and a quantum
confined energy level structure, enabling the realization of single photon
sources with high repetition rates and high single photon purity. Quantum dots
may also be triggered using a laser pulse for on-demand operation. The
naturally-occurring size variations in ensembles of quantum dots offers the
potential to increase the bandwidth of quantum communication systems through
wavelength-division multiplexing, but conventional laser triggering schemes
based on Rabi rotations are ineffective when applied to inequivalent emitters.
Here we report the demonstration of the simultaneous triggering of >10 quantum
dots using adiabatic rapid passage. We show that high-fidelity quantum state
inversion is possible in a system of quantum dots with a 15~meV range of
optical transition energies using a single broadband, chirped laser pulse,
laying the foundation for high-bandwidth, multiplexed quantum networks.
